Transmitts beam of I/R light across 6-8ft. distance. Use of 40 KHz modulated beam blocks out other sources of direct I/R light. When used with companion receiver; Kit can be used to detect objects interfering with beam, count objects, or as remote control. 6-12V DC Operation. IR3 L: 1" W: 3/4" H: 1/2" WT: .2