Energy efficient. The Mod Thermo Kitty Shelter is a simple zip together design. The rigid exterior will hold up to any use. Half the floor is heated by a K&H Small Animal Heated Pad so the cat can choose to be on or off the warmth.
The heater was exactly what I needed for my old cat that lives outside (I've tried unsuccessfully to get her to live inside). She was a stray but now she lives at my house and I wanted to make sure she was warm and cozy.