Onsen Island heater for crabs, perfect as a playground with a pool. - Product Name: Onsen Island - Purpose: Heater for hermit crabs - Features: Athletic house with a pool Thank you for viewing. I purchased this about two months ago and opened the box, but it was too large for my tank, so I didn't use it. I've put it back in the box and stored it at home. No returns accepted, please understand and purchase only if you agree.