This easy to use thumb driver is a comfortable diameter, light weight , with a knurled surface making those quick nut removals super easy. Seen here being used on Michal Orlowski's Cougar LD3, its great for 5.5mm (M3) shock nuts. - 5.5mm (M3) - Black Anodised with CORE RC branding. - light weight and compact. - Laser etched tool size for easy identification.