Made of heat treated chrome molybdenum steel with a corrosion-resistant black phosphate finish. These universal joints meet and exceed ANSI/ASME standards. The universal joint adopts the innovative ball design to evenly distribute the torque load on the larger surface area and improve the operation range, Full 360° degree motion allows U joint swivel sockets to access complete rotation to reach tight spaces, access hard to reach fasteners. Spring-loaded detent balls securely latch and through-hole in the drive end locks onto drive tang, It can effectively make up for the defects that the traditional universal joint may be stuck or broken. High contrast size marking is a permanent laser marker, which can be identified accurately even in weak light. Includes: 3 pc. impact universal joints One 1/4-inch. drive One 3/8-inch drive One 1/2-inch drive Designed for use with all cordless, electric, and pneumatic impact wrenches