This universal joint swivel set is made of CR-MO chrome molybdenum steel material. This material is resistant to high temperature and pressure, has strong impact resistance, and is difficult to be damaged by violence. Phosphate coating prevents rust and corrosion and prolongs life. The set contains 3 universal joints, namely 1/2 ", 3/8", 1/4 ". 3 sizes can meet different needs. It can be used in narrow areas or around obstacles, and hard-to-reach fasteners can be easily used. Widely used in various scenes, bicycles, automobiles, various mechanical car repairs, etc. 360 flexible rotation, more convenient and labor-saving. The universal joint kit can be easily placed in a convenient carrying case, making storage, transportation and organization a breeze. Material:Alloy Steel Number of pieces:3 Specification: Color: Black (As Pictures Show) Material: Chrome-molybdenum steel Dimension: 3/8, 1/2 and 3/4" drive connectors(Approx.) Package Contents: 3 x Set Sockets (3/8", 1/2", 3/4") Note: The real color of the item may be slightly different from the pictures shown on website caused by many factors such as brightness of your monitor and light brightness.