ALL-TAG's completely wireless People Counting System is a reliable, user-friendly, and affordable tool that will help almost any type of business operate more efficiently. The transmitter unit (PTX20-1) transmits two infrared beams to the receiver unit (PRX20D1). When someone passes between the 2 units and breaks the infrared beams, the internal counter increases by one. The Display Screen will flash the “In” and “out” counts separately so that determining the important “In” count can be done quickly and easily. The Counter can be rest back to zero at any time with the use of a special tool we provide. This Counter can be setup in minutes and requires no maintenance at all.