Really depends on what you want to do with it. If it's just a single tank to heat, for example, a snake, then the B1 is nice. I have 2 tanks to heat for a snake and a bearded dragon plus lots of lights for the dragon and I have the MICROclimate Prime 2 which allows me to monitor and heat up to 3 separate tanks (or 2 and lights) all with the one thermostat. They can be set to dimming, PP or On/Off and they have the added advantage of a ramp time option, so you can slowly increase your temperature over a few hours like... the environment. They also have data logging. It's a bit more expensive (I bought mine from the UK and changed the plugs cos it was cheaper) but probably one of the best I've found for multi-tank logistics.