This is the product we use here at Pritchett's Small Pets for our surface area in our Breeder colonies. This product is washable and reusable for a long time. I like this much more than excelsior because it is reusable and I love to reuse and recycle! This is the product to have. When your cultures are done producing, remove them and wash them. They are also so cheap if you wanted, you could recycle them and just order more. You are buying them in packs of 10.