The Samlex SA series inverters powers devices from its built-in electrical outlet. Its advanced microprocessor design allows for greater than 89% peak efficiency at full load (92% for the 24 Volt model). It is capable of both 50 Hz and 60 Hz operation by the flip of a switch. It has two separately controlled cooling fans so that it can optimize efficiency. The second cooling fan only turns on if necessary. The SA units also come with the following built-in protections: overload, short circuit, leakage, low and high DC input voltages, high temperature and reverse polarity. Meets UL-458 and complies with FCC Part 15(B), Class A.