+ Measure power drawn during normal usage
+ Batteries to store readings so that you can plug out from mains before taking readings
+ Show voltage, current, watt, duration, KWh, cost based on KWh and clock
- Inaccurate, seems to give larger values than actual power drawn. Give 17W reading for a 13W lamp
- Doesn't show low values. For some devices, e.g. clock, it gives a reading of 0W. The lowest reading that I have is 7W, hence it doesn't show anything between 0-7W and is not suitable to measure low standby power drawn accurately.
- Too wide to insert into some power extension plugs, will eat into space for next plug
If I have read "Howard Wright" review first, I would have buy the other meter instead of this. Although the other meter does not have batteries, you can work around it by using extension cable/plug. However you can't work around the inaccuracy of this meter.