This is an Optional Heavy Duty Motor Washer kit for Pro-Line’s Performance Transmission. Pro-Line now offers Heavy Duty Motor Washers and Screws to make sure motor stays where it should – Putting the Power Down! The Blue Anodized Machined Motor Washers allow you to tighten down the motor more than ever before and reduces the chance of your motor moving from hard impacts. This is a great upgrade for all of you that like to run high powered brushless motors! Get your HD Motor Washers today!