I currently have a glass aquarium and a metal wheel. I use olive oil so the wheel doesn't squeak, but it rattles against the bottom really bad. I want to get the habitrail sport wheel: http://www.critter-cages.com/index.php?main_page=product_info&cPath=46&products_id=364&zenid=73817d7b38bf2877b0d799a4549b29d5