The STB series Self-checking Optical Touch Button that are touch-activated photoelectric devices designed to replace capacitive touch switches and mechanical push buttons. Their outputs activate while a finger is in the "touch area" (yoke) of the switch, interrupting the button’s infrared sensing beam. Banner STB Series buttons are ergonomically designed to eliminate the hand, wrist and arm stresses associated with mechanical push buttons. LED indicators light when power is on and outputs are activated. All models are immune to EMI, RFI and ambient light interference. STBs have a black polyetherimide upper housing and yellow PBT base. Rugged yellow polypropylene (TP) field covers are supplied with all models to prevent inadvertent switch actuation due to objects (such as loose clothing or debris) which might accidentally block the sensing beam.