The K&H Pet Products Kitty Sill gives your cat an elevated spot where she can keep an eye on the neighborhood or settle down for a nap. Cats love being high off the ground, and this sturdy sill makes the perfect perch. No tools are necessary for installation when using the provided fuzzy fastener-style fasteners. However, you can use the screws included for a more permanent attachment. The solid design is made with pet safety in mind. It includes a soft, machine-washable fleece cover and a thick, comfy orthopedic foam. The adjustable brackets fit any window sill and it holds up to 40 pounds.