This should be the earliest model of the BHB Serie. Wooden box is still quite big (ca. 17 x 10) and equal to the size of other Old Germans (see below). At the same time, clock movement is not "Gebr. Hauser" anymore (like Old Germans or Posingis), but similar to the early Jerger era. In addition: long metal flag, metal second hand as well as logo "BHB". Produced late 1950s or even earlier.

Almost identical to the earliest model, just wrupped up in the Bakelite case.

Photo: Lisa Lane (Russia, 1961).

Almost identical to the earliest model, just movements were slightly 'upgraded'.

Photo: a match Luxembourg vs. Spain (May 3rd-6th, 1958).

Later wooden BHB, this time slightly smaller (ca 15 x 8.5 - basically, equal to the Bakelite brother). Second hand and flags are done from the plastic. Based on the stamp inside the clock, this chess clock was produced 02.11.1969.

Plastic BHB from the very late 1970xx, designed for the rapid & blitz games. There is just one hand (namely minute hand); the whole turn corresponds to 20 minutes (ideal for the rapid time control). Appeared in the American 'Chess Life' Magazine in 1982. Photo: occasional game, chess club 'Schwaz' (2010, Austria).