A ZapperBox can be used to record, or watch live, as many programs as the number of tuners it has. The quad tuner can do four, the dual can do two, and the single - one. The Zapper Mini does not have a tuner but it can be used to watch recordings or live TV from other ZapperBox devices in the home.
On all three models, while all tuners are being used for recordings - you can still watch a recording locally and also stream a recording to a remote device like a Zapper Mini.
The quad and dual-tuner versions of ZapperBox has the following advantages over the single tuner:
1. While one tuner is being used to watch TV, another tuner is used in the background to keep updating guide data being received over the air on other frequencies. This way, whenever you press the guide button, you see the most current guide data. See FAQ #45 for a much more detailed description of how guide data works.
2. Secondary tuners can be used to record a program that is not currently being watched.