1.Round and Vertical Replacement Options – We offer these cat scratcher refills in both round, narrow, and wide cardboard options which can be used to replace scratchers in many different cat toys for more universal scratching support.1 X 6" Inline Smart Controller Duct Fan 1 X 6" Carbon Filter 1 X Grey/Black 6-inch Flexible Ducting 3 X Stainless Steel Clamps 1 X Grow Room Glasses 2 X Lifting RopesVentilation Kit Inline Duct Fan Carbon FilterDisposable and Recyclable Paper – When playtime is over and it’s time to dispose of your shredded cat cardboard scratchers rest easy knowing they’re made with genuine paper, which means they can be recycled with other cardboard products.2.Heavy-Duty, Claw-Safe Materials – These corrugated cat scratchers are made with a high-quality wood paper that’s strong enough to stand up to sharp claws and little teeth, so it provides long-lasting support for all your indoor felines.3.Heavy-Duty, Claw-Safe Materials – These corrugated cat scratchers are made with a high-quality wood paper that’s strong enough to stand up to sharp claws and little teeth, so it provides long-lasting support for all your indoor felines.4.Promote Healthy, Active Play – Important for supporting your cat’s natural hunting, pouncing, and clawing behaviors our cat scratchers for indoor cats can even be used with catnip to get them excited about playing while keeping them physically active.