This is an optional pack of two XRAY T4 2020 Slim Batteries Adjustable Battery Holder, intended for use with the T4 2020 1/10 Electric Touring Car Aluminum Chassis Kit. These parts are CNC-machined battery backstop for the adjustable battery holder for positioning batteries fore-aft and left-right. These are designed for the slim battery pack. Allows for quick and easy weight transfer adjustment and are made from 3.0mm premium-grade graphite material.