The Alpha Communications SF117/2A Emergency Pull Switch features a rugged, long-life, positive-acting switch mounted on a durable ABS plastic faceplate. Signaling an emergency requires just a short pull on the 6' long nylon cord, in any direction. The signal cannot be canceled except at the point of origin. The SF117/2A provides two circuits to operate 1-2 signaling devices, such as a remote annunciator lamp, and a corridor dome lamp. A different model ( SF117/4C) provides two additional signaling circuits to operate additional options such as floor bell(s) and individual apartment electric door openers, as needed, but does not have the RED 'Call-Placed' Flag Indicator. The SF117/2A features a rugged, long-life, positive-acting switch mounted on a flame retardant type ABS plastic faceplate marked "EMERGENCY" in Black lettering. In addition, the SF117/2A features our 'Exclusive' RED 'CallPlaced' Flag Indicator which gives positive visual assurance when a call is placed, without the need for any additional power or station wiring.