This is a T50 internal Torx (star) impact bit socket that has a 3/8" drive size. It is designed for high torque applications with impact wrenches, but it does not limit the torque to a specific value itself. It is piece of the Grey-1234T set.
T50 Socket
Details
Drive Size: 3/8"
Star Size: T50
Material: High quality chrome-molybdenum alloy steel, engineered for impact use
Function: Designed to transfer pressure efficiently to reduce wear on fasteners and the socket, and to withstand high impact torque