"I have been using this type of tester for many years now, and as an addition to a neon tester both kept in my pocket this tool will save you from getting a meter out of the van for a quick diagnosis. If you turn up to a 'dead' washing machine for example, you can hold it by the blade next to the power lead and if it lights up you have confirmed the fuse is good and there is power at the socket. I never use it to touch the blade to a live circuit, that's what the neon tester is for. HTH."
"Like most other reviewers,has plenty of features.but I am not electronics expert and just want to prevent electrocution! Not much use if it gives a live reading with the power off,slightly defeats the object. it is obviosly detecting some residual power from somewhere?"
"The web page description and the packaging claim numerous functions: contact mains testing (AC and DC), non-contact mains testing, microwave detection and DC polarity detection. The instructions, however, do not mention the last two so how they might work is a mystery. It seems to work reasonably well at non-contact AC mains detection, if anything a little too sensitive. But there appears to be no means of using it for contact mains detection if it is near a live conductor (which gives a non-contact positive reading). So, if I believed this device, the (earthed) fixing screws on a plate switch were live."
"Like all the others, I bought a few of these and ended up dumping the battteries and using as an ordinary screwdriver. Totally confusing, you have absolutely no idea of what's live and what's not. Please bring back the old neon type where you stick your thumb on top and if it's live it lights up!!"
"Screwdriver didn't look like the one in the picture, this one was amber with a red LED where you'd expect the neon to be. Also, it runs on a pair of watch batteries. LED flashes when blade is in contact with a live wire. Or a dead wire. Or an earthed wire. Or ANY metal for that matter (even a 2p piece sets it off). In fact, even certain parts of my MDF computer desk (with everything disconnected) set it off! When you're using it as a screwdriver it flashes merrily in your hand, which is annoying to say the least. Best thing to do is to take the batteries out and use it as an ordinary screwdriver (although even the batteries are too small to use in anything else). Manufacturer suggested the batteries were in back-to-front. Turned them round to find that it wouldn't work at all, so that's obviously not the case. I ended up buying a proper mains test screwdriver (in other words one with a neon indicator and a resistor instead of a board full of faulty electronics) elsewhere. In a nutshell, avoid."
"The Kamasa multi function tester that I have just purchased indicates that something is live when it isn't . Backboxes and retaining screws for example and even a wire feeding a light switch is said to be live even though the main fuse is removed. I have held the wire in my hand knowing that the fuse has been removed but the tester red light blinks indicating that it is live. No part of my hand is on the top of the tester while doing these tests. I have informed Screwfix hoping they can advise me."