2 Pack Watt Meter Power Meter Plug Home Energy Monitor Electricity Usage Monitor, Electrical Usage Monitor, Energy Voltage Amps Meter Tester with Backlight, Overload Protection, 8 Display Modes

They work perfectly.

this was an "open box" sale and recived and found 1 screen cracked, unit still seems to work fine so thats why i did not return. items were packed in what seems to be the original packing, but should have been inspected better.

Seems to work fine

Funciona bien y es clara y precisa.

Claimed accuracies: Voltage: Plus or Minus 1%, Current: 2%, Power Factor: 2%. Results of my test: Voltage: Reads 1.5% low, Current: Reads 7-10% low, Power Factor 14-16% high. I bought a 2-pack, and both units agree within 1% of each other. Voltage was compared with an accurate multi-meter, my computer's UPS, and my old Kill-A-Watt tester, all of which agreed with one another within 1%. Current and P.F. were compared to the Kill-A-Watt tester only, using a pedestal fan, checking the 3 speeds (thus the ranges shown above). The voltage test is of high confidence (the 3 comparing devices), and the no-name tester is only slightly out of spec, so I have no complaints there. I have less confidence in the current and P.F. comparisons, since I only have the Kill-A-Watt device to compare it to, but since the K-A-W voltage accurately matches the multi-meter and UPS, I estimate it's current and P.F. readings are fairly accurate too. And to be fair, since the tested load was only 20 to 35 Watts, it's possible the no-name device's accuracy might improve with a higher load....I might test that in future. Bottom line, is that while the voltage is of acceptable accuracy, most folks buy this to check the current/watts, to monitor cost, and here it's of questionable accuracy. As to the Power Factor, as I understand it, power companies don't charge residential and small businesses for low power factors, so the inaccurate reading here is of little importance. So for ten bucks each, I cannot complain at all, just be aware you might want to calibrate your readings to a known good device before expecting the stated accuracies.