6-12V DC High/Low Tester, Use On 12V DC Automotive Circuits To Determine Whether The Circuit Is Live, Simply Clip The Insulated Alligator Clip To The Frame Of A Vehicle & Plug The Other End Into The Tester, Pierce The Steel Tester Point Through The Wire Insulation Of A Live 12V Dc Circuit, If The Light Bulb In The Tester Illuminates, The Circuit Is A Live Circuit, Handle Of The Tester Is Tinted So As To See The Bulb Illuminate In The Sunlight, With 3W Bulb, Tinted Handle, 6-12V DC Wire Piercing.