NO PURCHASED PARTS other than the replacement blades and maybe a little super glue!!!! Similar to a Milwaukee Fastback folding utility knife but with a slightly different locking mechanism that I prefer for casual use. Please give it a try and give me some feedback on the design, print quality or improvements! Assembly instructions are provided! If I am not careful when assembling, some of the pins and sockets do not work quite as well so I put a small drop of glue on the parts before assembling.