Made from virtually unbreakable and shatterproof ABS. The handle, pocket clip and blade are insulated for maximum safety. Made to VDE specification 0680- Part 6 - 4.77 To test the circuit place the screwdriver end on the electric contact and press your thumb against the metal contact next to the neon viewing window, if the contact is live the bulb will light. IMPORTANT:- Check that the neon bulb is in order by using the tester first on a known live circuit. Never touch the uninsulated part of the blade when testing.