Does anyone know where I could get a screen lid like this a la carte? It's supposed to sit mostly flush on top of the tank and has rotating knobs that lock it in place, along with the feeding door. I've only ever seen them for sale as part of kits or combos like in http://www.petsmart.com/reptile/terrariums/all-living-things-reptile-terrarium-zid36-20350/cat-36-catid-500028