Floor to Bottom of Door Opening is 8

you can build it with CritterTrail fun-nels

Resealable Bag

Can be attached on either side of the casing for right or left-handed users

River Jack Aquarium Gravel - Non-Toxic, Colorfast, Vibrant Substrate for Aquariums, Terrariums, Ponds & Crafts Reptile & Amphibian Medication Product Floor to Bottom of DoorNatural River Jack Aesthetic: Smooth, naturally colored stones create a rustic, riverbed inspired look, enhancing aquariums, terrariums, and decorative setups. Non Toxic & Safe: Made with a 100% acrylic coating, this gravel is non toxic, colorfast, and will not alter water chemistry, ensuring a safe habitat for aquatic life. Versatile for Various Uses: Ideal for freshwater and saltwater aquariums, terrariums, ponds, potted plants, vases, and craft