FAQ Explorer System

Here you will find answers to your questions about the Explorer System.


A forearm prosthesis is an orthopaedic device that attempts to partially or completely replace a body function.
The prosthesis consists of a socket and various activity modules. Depending on the activity, the modules can be easily exchanged.
Yes! The socket is a custom-made product, risk class I, and the ring and the modules are accessories of a medical device, risk class I. We have developed the prosthesis according to ISO-13485 and the Medical Device Regulation.

Target group

The Explorer System can be used for unilateral amputees from amputation height transradially or in case of dysmelia in forearm fittings (according to ISO 8548-2:2020). The system is suitable for persons from 2 years of age. In the case of very young users, we recommend clarifying together with the parents and the doctor whether the child can actually receive the desired benefit from the aid. The activity Modules can also be used independently of the macu4 Explorer socket after consultation with the specialist.
The macu4 Lynk System, like the Explorer System, is a very modular, lightweight and trendy tool. It offers a wide range of possibilities in terms of fit and the activities it can support you in. The Explorer System is suitable for people with amputations or congenital deformities below the elbow. Occasionally it can also be used by people who have a wrist. The Lynk system is suitable for people with a wrist joint and no or limited gripping function of the hand.
The Socket of the forearm prosthesis is individually adapted to the arm. We have developed a design for the macu4 socket that can be adapted to different - but not all - arm shapes. Your clinical orthotist prosthetist can advise you on this. Of course, you can also contact us directly, as we are constantly developing new designs. If the Explorer socket does not meet your needs, our next design may offer a suitable solution for you.
The Explorer System can be tested for a fee. Please contact the macu4 support team.
This must be assessed on a case-by-case basis. However, the socket can always be fitted with additional padding. If you are unsure, please contact us so that we can find a comfortable solution together.
The arm stump should ideally be at least 65mm long so that the socket has a reliable hold on the forearm. This is measured in a straight line from the medial epicondyle (the small bony prominence next to the elbow on the inside of the arm) to the end of the stump.
The arm stump must be approximately rotationally symmetrical. This means, for example, that no fingers should protrude from the sides. In case the arm is too curved, the Explorer socket is unfortunately not suitable. If it is not clear how an arm shape is to be assessed, we are happy to look at the respective case individually. The socket guide for professionals also provides a good basis of information for assessing when the Explorer socket design can lead to a satisfactory result.


Depending on the activity Module, different activities can be carried out. Various examples are listed under the heading 'Activities'.
Yes. The macu4 Explorer System consists of a Socket component, a Ring (connector component) and several activity Modules. The activity modules are designed for specific sporting activities. For example, the Bike Module can be attached to a bicycle handlebar.
Although most of the Explorer System Modules have a strong sports focus, they can occasionally support everyday activities. For example, the Pinch module can be used to hold cutlery and cooking utensils.
We are always happy to receive feedback. If you have any suggestions for further product development, please send them to us via the contact form.
The macu4 forearm prosthesis can be used for over two years with an average of 120 minutes per day of daily use.
Our products are passive functional tools and therefore do not require electronics. Electricity or batteries are accordingly not necessary.
The risk of injury when using the macu4 forearm prosthesis has been tested and is minimal when used properly. The prosthesis should not be used if there is pain in the forearm.
Depending on where the pressure points are located, there are various measures that can be taken. Often it can already help to loosen the lacing system a little or to turn the arm in the socket by a few degrees. If the pressure point is at the end of the residual limb, a disc or ring of cushioning material can help there. Since every arm is different, we cannot go into all scenarios here. If the above measures do not help, we recommend talking to us or an clinical orthotist prosthetist about the pressure point.
The macu4 Explorer socket can be used with a prosthetic sock or silicone liner, for example, so that the socket does not rub against the skin. Further information can be found in the macu4 instructions for use. A clinical orthotist prosthetist can advise on the choice of additional product.

Application - Modules

Yes. The Swim Module is made of polyamide-12. This material is suitable for water, chlorinated water and salt water.
No. The bike module cannot be used to operate the bike brake.
In principle, the macu4 Explorer activity modules can also be connected to other socket systems. The modules are equipped with an M12 x 1.5 or a 1/2″-20 UNF thread and can therefore be made compatible. If you would like to use a module with a socket other than the macu4 Explorer socket, please contact your clinical orthotist prosthetist.
No. All Modules are newly manufactured. Only when it comes to product testing, used components may be provided.
Module and Socket are connected by means of a Socket Ring with a screw thread. Before the module completely loosens, a few turns are required and a clear slit would already be visible. The ring can also be used to adjust the friction in the thread. If the module should loosen, it is immediately noticeable how this friction resistance is released.

Regulatory requirements

All so-called accessories (e.g. coupling component or modules) are CE marked and provided with a unique identification number (UDI) as soon as they are officially offered on the market.
The Explorer System has been developed according to the highest quality requirements along the Medical Device Regulation and ISO-13485.
Yes, the components are made of biocompatible raw materials. The raw material used for printing the socket is PA 2200 and approved for direct skin contact. The raw material is biocompatible according to ISO 10993-1, ISO 10993-5 and ISO 10993-12. The colouring material complies with the recognised requirements of OEKOTEX® Standard 100. The colouring material is biocompatible according to ISO 10993-1, ISO 10993-5 and ISO 10993-12.


Detailed information on this can be found in the data protection information.
The measurement from the arm can be done by photo or scan. A smartphone or digital camera can be used for photo-based measurement.
The measurement from the arm can be done by photo or scan. A smartphone or digital camera can be used for photo-based measurement.
The steps in the instructions must be followed exactly so that the required parameters can be read from the photos.
We extract the outline of the arm from each of two photos. This allows us to digitally reconstruct the geometry of the arm with sufficient accuracy to create the Explorer socket.

Use by professionals

By contacting us via the contact form, we can arrange an appointment to show you the functionality of a sample. If desired, we can also do this in a first step by means of a video call.
In principle, the macu4 Explorer activity Modules can also be connected to other socket systems. The Modules are equipped with an M12 x 1.5 or a 1/2″-20 UNF thread and are therefore compatible.
The online configurator of the Explorer system is intuitively designed. There are also specific instructions and videos for explanation. A separate chapter is linked to this in the footer of this website. Specialists have the possibility to configure the Socket and the Modules directly.
Basically no. But we are always open to ideas and requests.

Properties - Material

All materials used that come into contact with the skin have been dermatologically tested.
Almost all components of the Explorer System are made of polyamide-12. This is a material that is often used in medical technology. This material is resistant to water, chlorinated water and salt water. There are individual Modules that are made of polypropylene.
The screws and nuts we use are made of stainless steel. The padding materials are common materials for orthopaedic technology.
Our forearm prosthesis is mainly made of polyamide 12. This material is often used in medical technology. The material is resistant to water, chlorinated water and salt water. The screws and nuts we use are also rustproof.

Properties - Comfort

The weight of the macu4 Explorer system is a maximum of 300g (Socket with activity Module). More detailed information on the individual Modules can be found on the respective Module page on this website or in the instructions for use.
The Explorer Socket is designed to be very light and airy. Nevertheless, sweating cannot be ruled out, as this depends on many factors such as the ambient temperature or the intensity of an activity.
The Socket structure is provided with generous perforation - this has a heat-balancing effect when the Socket is used with a prosthetic cotton sock, for example. It is therefore relevant that the component worn on the skin for protection is breathable.

Properties - Product care

Yes. The padding material is attached to the inner wall of the Socket with a Velcro fastener and can be easily removed. We recommend hand washing with mild soapy water. Afterwards, the padding material should air dry. The padding material should always be detached from the Velcro fastener slowly so that the Velcro fastener does not detach from the inner wall of the socket. It is best to contact the macu4 support team so that they can give you a few tips and tricks.
Colour wear is a normal sign of use.
The system is best cleaned with water and a cloth. Further information can be found in the instructions for use.
The main component of the prosthesis is made of polyamide-12 (PA12). The post-treatment of the material surface provides little surface for invisible dirt and bacteria to attack. Almost all 3D printed components are made of PA12 - the instructions for use list the specifications per product component.

Properties - Configuration

The colour can be selected when ordering. There are different options depending on the product.
The macu4 socket is custom-made to fit your arm. The matching Modules are available in two different standard sizes.
The circumference of the prosthesis is variable within a certain range. It can be adjusted by means of a lacing system. The inner wall of the socket is also compensated with a cushioning material. If necessary, a thicker padding material can be used.
The material used is a thermoplastic. Any change to the socket wall can alter the mechanical stability. Therefore, thermoplastic deformation is not recommended. Subsequent thermoplastic deformation is prohibited for sockets manufactured by macu4.
The Explorer System is very light, but would still not float on the surface of the water.
The macu4 Socket is only ever designed to be as long as the arm stump. That is why the Modules are available with different lengths of length compensation. A specialist or macu4 can help with advice.
The maximum length of a spacer is 195mm.
No, unfortunately that is not possible. But the clinical orthotist prosthetist can assess whether the previous Module with its spacer length can continue to be used when manufacturing a new socket.
No length compensation is necessary to swim comfortably.
Please consult the specific Module page. There you can find out which product sizes and configuration options are available for each Module.
linkedin facebook pinterest youtube rss twitter instagram facebook-blank rss-blank linkedin-blank pinterest youtube twitter instagram