Instruct: Classify an Amazon review as either positive or negative.
Query: So far worth the purchase...

I purchased this for a ferrel cat that I have been housing outside. It appears (i've had it for 2 weeks now) to be working fine and stays warm for around 8-9 hours. I read other complaints that it was too hard. For my cat I put it on a pillow case filled with straw and then put a small fleece blanket over the top of the pad inside of a small cat carrier. The cat stays in there all night and seems to stay pretty warm. I removed the small fleece cover for some extra heat. If you can afford it I would suggest purchasing two so that you can have another one ready to heat up without having to wait for the 1st one to completely cool down (which you need to do).