There is no difference. X-10 was invented in England, marketed and sold here in the US under the BSR (USA) name starting in 1978 and then offered to RadioShack first, and Sears, second, for distribution under their own brand names. BSR later became X-10 (USA), which is the original inventor of the technology, sells X-10 under the Powerhouse brand name, RadioShack used their own brand name "plug n'power".