This Keystone is CEE Qualified, cUL, FCC Part 18 (Class B), NEMA Premium, Sound Rated: A, UL certified and works in temperatures ranging from 0oF, -18oC -> 167oF, 75oC. This product is recommended for Commercial use, with an input voltage of 120-277V and 50/60 Hz input frequency. A 3 Year warranty is also included in the unlikely event a problem arises!