Each key can record up to 999 with the exception of the totalizer unit which records the total number of strokes made on all the other keys.Weight: 770 grams, Length: 31 cm, Width: 8 cm, Height: 5.2 cm.It is having 8 keys and 1 totalizer unitto count the Basophil, Monocytes, Eosinophil, Myelofibrosis, Juven, Stab Cell, Segmental Neutrophils, Lymphocytes for other miscellaneous cellsAt totals of 100, 200, 300 and so on the totalizer unit rings a bell.