Sperry Instruments ET64220 Wire Tracker Wire Tracer, Audio / Video Installers Must-Have, for Coax, CAT 5, Speaker & Phone, Adapter plugs: RJ-45, RJ-11, Coax & More APPLICATION: Wire-tracer is a must-have tester for audio/video installer and data com technicians DESIGN: Adaptor plugs include: RJ-45, RJ-11, coax, automotive fuse blade and insulated clamps DESIGN: Adjustable sensitivity and positively identifies a single wire when multiple wires are routed in close proximity DESIGN: Operates from (2) AAA batteries for the transmitter and (4) LR44 batteries for the receiver (included) FEATURES: Audible and visual indication and an auto-shutoff after 45 minutes