Set of 4 pieces. Gray material: Specially formulated hard material prevents blades from turning. Black material: Soft TPE material is formulated for best torque transmission and has integrated pattern area for better hand grip. Rotating cap with anti-slip surface. Size marked on blade with permanent laser etching. Exceed ASME B107.600, ISO 2380-1 & ISO 8764-1 standards. Screwdrivers sizes included: Phillips type tip: PH00, PH0, PH1, PH1.