The medium humid hide contains four (4) sponges in an easily opened compartment. Just add water to these sponges as needed, typically every 3-5 days, and your reptile will have a secure, humid hiding area. These are just what you need for many desert gecko species and small snakes with shedding issues. Dimensions: 9"x6.75"x3" These hides are made of heavy 1/8" thick polypropylene and are nearly unbreakable. Unlike competing products, these have the door offset so your snake can really feel secure rather than much of the front being exposed. Remember-You want to select a hide that will be a snug fit for your reptile. If it is too big it will not offer the security they need! Comes with Hidebox, Lid and four (4) sponges. Replacement sponges are available in 10 packs. Sponges are super easy to sterilize- saturate them, place on a small, microwave safe dish and microwave for a few seconds. Be CAREFUL! They will be very hot when you remove them. You can also saturate with F10 solution, let stand for 10 minutes, rinse and you are ready to go!