Do your KC-02 CO2 mags leak from the puncture pin device? Did you order the spare parts (Parts 188 & 189 from the v2 manual) to replace them with from KJW's excellent customer service department in Taiwan? If so, now you're stuck with how to change them out and have I got the tool for you! Just drop in this nifty 3D-printed Stainless Steel tool and you'll be able to swap the parts out in no time using the Allen wrenches you already have laying around. Nuff' said!