any DINN 1 size will work, it's just the mounting hardware that will differ. I bought an Alpine IDA x200 which is an ipod/usb/tuner type with no cd player. I wanted to play from a flash drive and it reads it just like an ipod, or it plays an ipod while it charges it, and you don't have to use the ipod to select music. Hog Tunes is recommended by many hear and the addvantage is the interface with the handlebar controls and mounting systems although there is a limit to the brand on stereo available.