Fixes most light sets in seconds by addressing the damaged bulb at the plug or at bulb socket. LED headlight helps visibility in light repair. Audible continuity detector traces the circuit to the point of interruption. 3 way bulb puller easily helps tight bulbs from the sockets. Bulb and fuse tester tests indoor or outdoor miniature bulbs. Storage compartment built into the handle is storage for bulbs and fuses. Three 1.5V batteries included.