Technolink TC-780i Mobile CD / MP3 / AUX Input Booster for Car Stereos includes two interchangeable faceplates (in-dash and under-dash) includes mounting bracket with side screws and allen wrench includes DC cord for mobile installation S/N Ratio: &gt;90 dB; Gain 10dB (with trimmer and output control set fully CW) AC adaptor for in-home use is OPTIONAL, and is NOT included