material: premium flex chrome vanadium steel drop forged, entirely hardened and tempered surface finish: trivalent chrome plated according to ISO 1456:2009 polished made according to standard ISO 2725-1 Simple use The operation of the ratchet accommodating the sockets is based on a 75-tooth mechanism, which divides the 360 full circle into sections of 4.8-degree angles and thus guarantees simpler use even at nearly inaccessible points. With larger ratchet increments, fewer turns and less effort, you can achieve greater reliability and higher precision. Accuracy Together with the indispensable ratchets, Unior sockets allow even, predictable and precision tightening and loosening of screws and nuts -working with Unior ratchets is safer and more accurate. Safety Special socket retention system with a one-touch release button ensures greater safety at work and an increased socket locking speed. Standards ISO 2725 - 1 Documentation pdf Socket 3/8", 6 point - 238/1 6p