Many patients with an upper-limb deficiency choose not to wear their prosthetic devices due to a multitude of reasons, including physical discomfort and unintuitive, cognitively demanding control methods. A new haptic interface was developed combining the desirable control characteristics of body-powered control prostheses with the comfort of an externally powered prosthesis. A study (n = 10) was performed on the effect of the haptic feedback provided by the interface in a stiffness perception task. Participants were asked to determine the stiffness of a object with and without visual and/or haptic feedback. The haptic feedback was provided through the newly developed interface and the visual feedback through the display of a virtual slave. Results indicate that there is no significant difference in stiffness perception between the conditions with visual and/or haptic feedback.