Professional triple square sockets for commercial or occasional use Stubby impact triple square bit sockets Spline / triple square Male sockets Also included tamperproof triple square sockets S2 impacted end for extra strength Male spline and tamperproof sockets so basically like Allen key ends, not like normal sockets (female) Spline sockets are also referred to as triple square sockets Triple square / 12 sided sockets this limits the amount of wear on the corners of the fasteners and the socket as you have more sides / teeth on the socket biting onto the item Stubby socket so ideal for access into restricted awkward areas Comes in a socket rail for easy storage and transportation 1/4" / 3/8" and 1/2" drive so will fit any standard size ratchets / bars Triple square and tamperproof triple square US Pro Industrial (brand) this is the more industrial brand of both Bergen and US ProSET INCLUDES THE FOLLOWING • 1/4" Drive Triple Square – M4, M5, M6 and M8 • 3/8” Drive Triple Square – M10 and M12 • 3/8” Drive Tamper Proof Triple Square Bit – MT14• 1/2” Drive Tamper Proof Triple Square Bit – MT16 and MT18Comes on a socket rail for easy storage and transportation