Watts up? are "plug load" meters that measure the amount of electricity used by whatever is plugged into them. NEW - now internet based models (.Net & SC20) are integrated to Google PowerMeter, so you can see your data on your Google home page. Fast, intuitive and easy-to-use, Watts up? quickly and accurately measures any 100- 250 VAC device. USA models are rated at 120v. However, all models are available with IEC 320 universal outlets (UO) instead of integrated USA style cords. Click the more link next to each meter below to see a photo of the UO versions. Universal outlet versions are rated at 100v - 250v, 15 amp, 50/60 Hz, and are also CE marked. Cord sets are sold separately, with country/voltage specific ends. Be sure to order the UO model when completing your shopping cart. The meters incorporate sophisticated digital electronics that enable precise and accurate measurements in an easy-to-use format. State-of-the-art digital microprocessor design utilizes high-frequency sampling of both voltage and current measurements for true power. Power factor is captured so even phase-shifted loads such as motors are accurately measured. All the meters areproudly manufactured in the USA.