Mechanical, benchtop counters are ideal for determining the number of cells, counting parts, etc. Use with blood cell label or insert your own. Each key records up to 999. Total window keeps track of the total number of stokes made on all other keys; at one hundred totals, counter rings bell. Counter with 6-key measures 250 x 76 x 56mm. 9-key counter measures 320 x 76 x 56mm.