APC Automatic Transfer Switch - bypass switch - 1440 VA

This is a well designed ATS, and may be a bargain if you can find one in stock, but it is worth the difference to go ahead and purchase the (slightly more expensive) newer model, the AP4450. It does provide all necessary functions of an ATS, and the transfer rate is within the industry standard and within the time power supplies will typically drop loads. There's not much difference between the two models, but the newer AP4450 has a better indication of the selected source.