When I would go out and bash my traxxas slash 4x4 I would always hit a rock or something and knock off a shock endcap or break one. So I designed a better, stronger endcap. I have yet to have one fall off yet. Hope you like the design, open to any improvements, but have not had one issue yet. Why go buy when you can print! Used on almost all standard Traxxas shocks and many other RC brands. Kyosho, associated, This item was made in the Creo software, designed from the stock Traxxas shock endcap. It is fitted and installes just like the stock endcap