Here is a cat door that gives your cats access to their litter box while your doors are closed. Purrfect Portal is easy to install, helping you manage odor in your home conveniently. This cat door is large enough accommodate larger cats up to 20 lbs. It works for solid and hollow-core doors, between 1.25″ and 1.75″ thick.
The Purrfect Portal has a cat silhouette design and works for laundry rooms, bedrooms, and everywhere else. Costs under $30 at this time.