It's a new product at the pet store. They come to fit certain size tanks. Some people fill the back half of the tank with sand & make it level. I just put it in there & since it's foam, they climb it easily.
I saw those at Petco for $25. its a cool idea, but its kind of pricey for a piece of foam. I think it'd be way cheaper if you bought a block of foam and just carved shapes out with a pocket knife, or whatever... do you guys know what kind of foam you could use to make this kind of stuff that wouldn't harm geckos ?