Revolution counters count the number of rotations in a variety of equipment. This counter may be connected to mechanical equipment directly via the shaft or using gears and pulleys that can change the ratio of the count. MS102B is usually mounted by two screws, but depending on the installation they may also be seated on an elastic pad.

MS-102B is a 5-digit Revolution Counter with Nylon body and ABS casting. The shaft is 10mm long, 3mm in diameter and is positioned on the right.