SIRIUS Sportster Replay - Sirius satellite radio tuner with RF modulator Internal memory continually stores the last 44 minutes of the channel you're listening to Built-in FM transmitter 30 channel presets/20-song memory (alerts you when one of the songs is playing on SIRIUS) Game Alert lets you know when your favorite team is playing Dimensions: 4-9/16"W x 3-1/8"H x 1-9/16"D DC power adapter ; Roof-mount antenna with magnetic base and 20-1/2' cable SIRIUS subscription required for operation