I use this around the outside of our 40gallon turtle tank in the winter. The room they're in can get chilly and I like our turts to be toasty. It does a great job. Turtles are tricky because they'll bite filters and heaters. Using this externally solves that problem and gives adequate heat when the lights are off
I use the cable to keep my 'spider shelf' warm. It's fantastic, and emits a suitable amount of heat. I have used it with several of my pets, and haven't had any issue. The cord also holds a consistent temperature from beggingg to end (unlike some others I have used), and is a great alternative to heat-lamps.