The goal of this book is to create a prosthetic limb prototype for above-knee amputees, especially those who cannot afford to purchase pricey and pricy, superior prosthesis. With this device, the user can stand, sit, and walk without experiencing any jerks or blowback. When compared to its high-end competitors, the product weighs comparatively little and is precisely sized to be a close duplicate of a knee joint. The conical spring used in the knee mechanism was made of spring steel and is totally cast in aluminum. The lower end of the knee is attached to the amputee's leg by a belt that can be tied around the knee joint mechanism's cap.