As far as i understand it, and I am a novice, the DVR snap on allows recording of video and audio from other sources - but not tv. It allows you to charge the unit faster, with an a/c adaptor not included. I think to record from TV you need either the docking station or the mini dock. The mini will just record, the docking station you can set to record using a scheduler. I also think the snap on will allow you to transfer from camcorder to unit....but I could be all wrong, all the different bits got confusing to me. Be careful there's a docking station, a mini dock, a battery dock and the snap on. Look carefully at what each does before you buy.
