A WWll wrist compass with an AF0210 strap sold on 1 October 2018 for £155 on ebay.
The Mark Vl wrist compass dates from WWl, but was issued in 1917 and 1918 as a hunter cased pocket compass with a bow. Just as military watches acquired wire lugs over the course of WWl, and leading into WWll, this compass acquired a slightly heavier blackened case, and lugs, in WWll.
The WWll wrist compass is shown below as sold on an AF0210 strap, which is not stamped with either the pheon (/l), nor AF0210. Later Mark Vl compass straps had identical hardware, but in stainless steel, with single ply DEF-3 webbing.
AF0210 straps were eventually designated Strap, Wrist, Instrument, and were not specifically watch straps, but are rarely seen stamped on a wrist compass, either the Mark Vl or the 6B/2593, which replaced the Mark Vl compass from 1955 onwards.