Sealey AK407
Price: £9.00 Earth lead length: 85cm
As with the Draper 57680 and Gunson G4166 (below), this simple device detects electricity at the probe and uses LEDs to indicate voltage. There’s also a plus or minus LED, which made us think the tool displayed polarity. But it doesn’t. While it shows a live feed as a +, feeds to earth (which should be negative) just appear to be dead. Blunt point makes connecting difficult, too.
