Intercall Guardian STC5 Infrared Staff Activation Device(pack Of 2). Personal Activation Devices are worn by all members of staff that require protection. Infrared Transmitter Confidence LED Push button activator - call level 1 Snatch pin - call level 2 (generally 'Attack') Both buttons are programmable and offer a number of levels of "call" type Transmit to wall mounted call points with infrared receivers or dedicated receivers mounted at high level