This has got to be the cheapest watt hour meter ever made! Poor quality, so poor that the meter stopped working with just a 2 amp load. The brake magnet is a tiny neodymium, which probably works well as a braking magnet, but the gears are very thin plastic. The worm and the worm wheel sometimes do not mesh properly and that's why the meter stops as the gears get jammed. I surely would not want this meter on my house monitoring my power consumption! Hmm, I wonder what Huadong means?