1 inch Drive Heavy Duty Professional Quality 72 teeth Ratchet72 teeth gives a working arc of just 5 degreesTwist reverse action for changing the rachet direction with one handSocket retainer and quick release in the ratchet head for added safetyCompact head design permits use in confined areasChrome VanadiumAll Teng Tools sockets and accessories are individually marked and manufactured from high quality chrome vanadium steel to comply with the latest DIN and ISO standards.All sockets are produced according to Teng Tools “hip grip” system, which means the socket grips on the flat surfaces of the nut rather than on the corner. This system helps to prevent damage to nuts and bolts and makes it possible to grip nuts and bolts which already have damaged corners.