ST Racing Concepts Mini Crawler Aluminum Thin-Walled Wheel Nut Wrench. Designed to fit in the tight spaces required on mini crawlers, this thin-walled wrench fits perfectly when used for wheels on crawlers such as the Axial SCX24, AX24 and Traxxas TRX-4M. Utilizing a 4mm socket on one side and a 5mm socket on the other, this CNC machined aluminum wrench makes maintenance easy and hassle free. Upgrade your toolbox today with this Mini Crawler aluminum thin-walled wheel nut wrench from ST Racing Concepts. Package includes one 4mm/5mm thin-walled wrench.