Prosthetics are some of the most common and oldest biomechanical devices in use. Upper limb prosthetic used in Congenital Hand differences, which are deficiencies that occur from birth, play a vital role in the functional capabilities of affected individuals. Desirable properties of the prosthetics include, appearance and aesthetics, comfort, and functionality. In this study, a 3D printed prosthesis with a desirable appearance and comfort was used to implement functional modifications to the device. The modifications implemented are that of dorsiflexion and an increase in thumb mobility to the existing device. These modifications are required to make the prosthetic biomechanically accurate in its function and increase its utility to the patient. The changes are designed into the prosthetic and the model is 3D printed to create a device that serves as a proof of concept. The results show that the changes made meet the project objectives. This leaves validation through a clinical study on patients as a future objective. Once this is done, the device can be released to the online community to be used and improved on a global scale.