Ultimate universal CNC-machined alu motor holder fits the standard M18 composite chassis as well as the graphite chassis. Allows you to use ANY currently-available micro motor such as a stock 180, micro modified, super size 300, modified motor and Orion Elite motor. The motor holder is great because it increases motors cooling (giving improved motor performance) and adds strength to the chassis. This motor holder features an adjustable alu insert that enables you to quickly and easily adjust gear mesh from the bottom of the chassis. The insert sits in a machined cavity in the holder, preventing it from falling out during assembly or adjustment - another smart XRAY solution.