Ti9mex Model B or B-21 watches were produced between 1945 and 1953. These shock-proof watches later evolved into the Timex Mercury range. the 21 in B-21 signifies the use of the M21 manual wind mechanical movement that was used to power these pieces. As non-waterproof watches, Timex Model B pieces were less expensive pieces.

There is little information from the 1940’s meaning identifying individual pieces is difficult. This is further compounded by differences between watches produced in the UK and USA.  As a result, many of the Timex Model B watches in my collection remain undated.