The Hero Arm is a 3D printed, below elbow prosthesis with interchangable covers. This set of fantasy covers is one of several in the museum's collection, collected to reflect the extensive collection of interchangable covers produced for the Hero Arm, which are central to its appeal to children and adults alike.

The design decision to give the Hero Arm a wide range of interchangable covers was made after consultation sessions with children and young people. Early in the development of the Hero Arm, Open Bionics founders Samantha and Joel invited a group of children and young people with limb differences to feedback on prototypes, and to explore what their dream bionic limb would look and feel like. The children and young people consulted indicated that they did not want to hide their limb difference with a lifelike prosthetic but would rather celebrate it with something fantastical. Live sketches of the co-design process record young users of prosthetic limbs dreaming of fingers containing lipstick, the power of robot super strength, or a completely customisable arm that they could theme along their favourite colours, films and books. The children's playful, proud and imaginative approach to their dream limb directly informed the aesthetic design of the Hero Arm, with a new emphasis placed on the bionic 'superhero' aesthetic and movement of the arm, and a range of fanstistical customisable covers, including collaborations with 20TH Century Fox and Disney (including the Marvel, Star Wars and Frozen franchises). As such, these covers are an example of child-centred design and the creative potential of involving children in the design process.