Review on AMOSIJOY Cordless Cat Window Perch with 4 Strong Suction Cups - Cat Hammock for Wall, Anchors & Screws Included - Solid Metal Frame, Replaceable Covers, Foldable Beds for Indoor Cats by Nancy Young

This is the best lip design I've seen from Revain. Everyone else sucks, seriously. They have wires, or need screws, velcro, or glue, or have "legs" that attach to the wall. This design is just smart. ➕ No modifications to the window sill required. No screws, just suction cups. ➕ No cords for your cat to get tangled in. ➕ No "minimum depth” required for sill. ➕ Interchangeable covers (easy to clean). The suction power is as strong as the first day after a month.