When we repair LCD screen or notebook and see a little shadow from very dark screen or 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 ! Support to 15 inch CCFL . Directly connect this tool to the monitor 12V power supply, and clip the both end of , you can light the CCFL . Attention:Be careful not to be hit by high voltage! Do not contact the metal parts when working. DIY Supplies: 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 Only the above package content, other are not included. Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.