Socket Tester, Plug Tester for Electrical outlets,ZT-E4, Leakage Detector with GFCI Test, Electrical Circuit Tester for Quick and Safe Wiring Diagnosis

Has a large color LCD display. YOU MUST BE MINDFUL OF ONE THING: THERE IS A GFI (GROUND FAULT INTERFACE) BUTTON, AND IF YOU PUSH IT, YOU WILL BLOW THE BREAKER ON THAT CIRCUIT! I have never pushed it, but I know what it is supposed to do. This is a great tool to have around the house to check electrical outlets.

The product is a good deal for $19. It's easy to use and easy to understand test results. However, the little folded instruction sheet is in such a small font that you need a good magnifying glass to read it. The instructions say to open the back cover and insert two 1.5V AAA batteries before using. The Amazon product literature also tells you that batteries are required. The instructions and the Amazon product info neglect to mention that the two batteries already come in the product. There is NO SEPARATE BATTERY COMPARTMENT. You have to unscrew the back cover and GENTLY pull it off, as wires attach the front with the circuit board and batteries to the back cover with the wall plug. The wires are not long enough to cleanly pull the back cover out of the way of the batteries. I always read and record alkaline batteries' voltage and change them out when the voltage gets low to avoid leakage and corrosion. It's very awkward to do with this product - the wires should be longer. In trying to measure voltage for the limited distance I could remove the cover, one of my leads slipped and touched both a battery terminal and the circuit board. I thought I'd fried the circuit board. The product wouldn't turn on with the cover on again. I opened the cover and replaced the batteries. That must have rebooted the device since it's worked well after that.It's too bad for all the nifty circuit detective electronics in the Zotek device that they don't display internal AAA battery status on the lovely LCD screen; it would be even better if such an indicator displayed the AAA battery voltage. It's very awkward to have to unscrew the back cover, pry the device apart, and take the batteries out to test voltage (to avoid slippery probe accidents like the one I had).Overall, I'm very happy with my purchase. I just don't look forward to checking battery voltage. I replaced the alkaline batteries with much more expensive Energizer single-use lithium AAA batteries. They don't leak even when dead and have a 20-year shelf life. So I'll only have to open the Zotek tester when my Li AAA batteries die, but two such batteries are ~25% of the cost of the Zotek tester!

Powers on and shows proper connection, what's missing and voltage between hot - neutral and neutral - ground. Helpful info for checking all proper aspects. Also does ncv test. Just be careful of the GFCI test button.

Used this to track down issues in a remodel that had a lot of 40 year old wiring. Extremely handy.

In Florida many Romex installations corrode at the sockets from high humidity over time. A high voltage spread from neutral to ground creates many issues with electronics like audio amplifiers that depend upon a low spread. I have seen many outlets with a 7-10 volt G/N spread and this often drops the hot line the same voltage. Many electronic devices begin to shut off below 110V so even if a decent hot line is at 117V systems can still fail, especially when nearby motors start up. Just a really handy tool to check if devices are acting funny.

This not only safety tests, but gives you a graphic as to what might be wrong. Tester also uses AAA batterie's which are already installed. Only one tester per order though graphic shows more.

When it's working it's a really nice tool. The day I got it I checked 4 recepticals in a fairly steady fashion, and it already let me know I had a missing groundPlugged it in to the 5th outlet, and the screen went dead and I was so disappointed I just up it in my tool bag and said oh well. I don't return this, if it's broke, or a linen, well that's the luck of the draw. About a week later saw it in my tool bag and changed the batteries and it worked. I checked maybe 8 recepticals and it was just perfect.It must has an auto shut off, because it did not shut off when I pushed the same power button I pushed to turn it on.Next day tried to use it and there was nothing but a black screen, until I changed the AAA batteries I just changed the day before, after that it lite right up.Used it that day 10 times, and no issues, I hope it works tomorrow, I out of batteries

Was exactly what I ordered and was shipped out fast, recommended seller