Britool Bi-Hexagon Deep Socket 1/2in Drive 18mm
is no longer available although you may find similar or newer versions below:
ISO 2725-1, DIN 3124, ISO-1174-1, ISO-1711-1, ISO 691.
The Britool BRIE117284B Long Reach 12 Point Socket 1/2 in drive 18mm has the following dimensions:Size: 18mmLength: 79mmWeight: 165g
The Britool 1/2 inch drive 12-point long sockets (metric) are crafted from chrome vanadium steel with a high chrome finish