Types; 129 - Miniature seven digit operations counter with a front bezel size of only 32x15mm. The 129 counter is only available in DC voltages and is suitable for either front panel or PCB mounting. 170, 171, 180 and 181 - Simple electromechanical operation counters, available in a choice of two front bezel sizes 36x4mm or 53x28mm. The counters are available with or without reset. On resetable versions the reset is via a front manual pushbutton. 663.6 and 668.6 - Din rail mounted modular construction grey operation counter, suitable for mounting within consumer units width 36mm (2 modules) and height 60mm. These operation counters benefit from an excellent shock and vibration resistance specification.