I have used Vision cages for many years and have many in use right now, several being 221s. I stack them with a heat pad under each one and never had a problem. I use the Exoterra Heat Wave pads as they are thin and I never heard of one burning out. I place the pad under the back center section in between the stacking ribs and attach the pad with aluminum foil tape around the edges. I did like the old style Heat Wave pads much better. Now I use the Desert model as the Rainforest model just does not provide enough heat through the Vision cage floor. A thermostat or rheostat is needed. Bill
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...three years ago it was just another snake cult...
The Retic is King.
Anacondas-the other Dark Side.
Afrocks-the dark side of the Dark Side.