This Lemania chronograph was produced in small numbers for just over 20 years, from the 1950s to the early 1970s, and has a monopusher mechanism based on the Lemania 2220 movement. Its black dial and large tritium hands make it very easy to read, and the thick asymmetrical case adds a touch of coolness. 
The dial features the broad arrow mark, indicating British Army ownership, and the T mark, indicating the presence of tritium on the dial and hands.