Ultra Safety Systems UPS01 12 volt. Senior model. Switch with high water alarm sensor. The ultimate in performance and reliability. Commercial grade construction. Impervious to all materials commonly found in bilges. Switch components completely sealed against moisture. Extra long wire leads with adhesive nylon butt splices. Optional backup alarm sensors available. UL listed. Exceeds U. S. Coast Guard standards. Wiring instructions engraved on the switch. Mounts easily. Simple to wire. NOTE: SWITCH ONLY. BILGE PUMPS SOLD SEPARATELY. Measurments: 2 1/2 diameter x 6 3/8 long.