This is the Sirius SUPH1 Home Dock. This dock allows you to charge your Sirius Satellite receiver as well as play it through your home stereo system. This home dock features a 5volt DC input, audio output, & antenna input. This dock is the same cradle that came in the SUPH1 Home Kit and is compatible with the Sportster 5 (SP5TK1), Sportster 4 (SP4-TK1), Sportster 3 (SP3-TK1), Starmate 4 (ST4TK1), Starmate 3 (ST3-TK1), & Stratus 4 (SV4TK1) receivers only.