When we repair LCD screen or notebook and see a little shadow from very dark screen or get inverter protection, it's very difficult to know if problem comes from the CCFL tube or inverter board. If we have this tool, easily find out the problem. Application Range: LCD backlight detection, LCD TV backlight detection, LCD maintenance display channel detection, CCFL advertising signs, motor angel eye headlights . Really a good tool for test LCD lamps! Support to 15 inch CCFL lamps. Directly connect this tool to the monitor 12V power supply, and clip the both end of lamps, you can light the CCFL lamps. Attention:Be careful not to be hit by high voltage! Do not contact the its metal parts when working. : ELECTRICAL Model Number: CCFL Lamp Inverter Tester Voltage: 12V colour:Blue Material:Plastic + Metal Package Contents: 1 x LCD CCFL Backlight Tube Tester 2 x connecting extention line Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.