6-point socket 20mm, 1/2" square drive, 38mm long.  Endura brand (part of the Greenlee group based in USA), industrial quality.  The socket is made from chrome vanadium for toughness and wear resistance, chrome plated and highly polished.

We have lots of other sizes listed including 3/8" and 1/2" drive allen key and 3/8" + 1/2" drive Torx ended in various lengths- see our other listings.

FREE POSTAGE UK!  We always post items quickly, but if you need it fast please consider taking the 1st class post or next working day courier (England/Wales mainland only) options, as 2nd class post can be very slow.