My application required the three-prong feature, or for me to use multiple adapters. The only switches in my local hardware store were two-prong, so this suited my needs. Now, my application is for an overhead lamp in the laundry area of my garage. It has a power cord hanging down from it to plug into a wall AC socket. No switches. This product has an LED light embedded in the switch. Except it ‘lit’ when the switch is on, and dark when the switch is off. This is a bit counter-intuitive for my application – I would rather have the swtich lit when the overhead light is off so I can navigate to it in my darkened or dimly lit (depending on the time of day I do my laundary) garage. But it works the opposite of that.
Electricity cost/kwh can easily be set, and co2/khw can be set as well. Averages tell you the yearly/monthly cost based on duty cycle / historical usage. I read the 1-star reviews and there are some mistakes and misinformation there, however, one legitimate complaint is that it does not give you total KWH used since beginning a measurement. You can back-out the math to easily calculate this based on the yearly cost projection if you know the amount of time spent measuring, but this is a legitimate shortcoming that it can’t simply display the number. Overall however, a VERY well thought out product and still squeaks by to deserve 5-stars.
This is very handy when you have devices that continue to draw power when “off” (like electronics with power bricks and other so-called “vampire” appliances that constantly draw power) or appliances for which you want to have extra assurance that they’re off (e.g., irons). Given that U.S. power outlets down’t have switches, I usually unplug such appliances. This solution is more convenient. It essentially introduces a power switch right at the outlet, cutting power completely to whatever is plugged in when you toggle the switch, without having to unplug the device. It’s like a power strip without the big strip. It’s a relatively low cost and very convenient way to completely cut the power without having to unplug and replug appliances all the time. I sort of wish U.S. electrical outlets were wired with this functionality, as in the rest of the world. In the meantime, this is a relatively cheap and simple solution.