The 1/2 inch drive 12-point long sockets' class='desclinks'>sockets (metric) are crafted from chrome vanadium steel with a high chrome finish. The OGV® profile allows tightening torque to be applied to the sides rather than to the angles of the nut. This product is for manual use only.

ISO 2725-1 - DIN 3124.

The Britool BRIE117286B Long Reach 12 Point Socket 1/2 in drive 21mm has the following dimensions:
Size: 21mm
Length: 79mm
Weight: 200g