The patent pending K&H Kitty Sill - EZ Window Mount™ is the easiest, strongest, most versatile window sleeper on the market. We’ve incorporated 2 push ’n’ turn suction cups and 2 giant push cups for the ultimate in strength. These things suck! Really! Each suction cup holds in excess of 100 lbs. yet is still easily removable for cleaning. Exclusive design allows for window blinds, curtains and shades to operate normally! Cover easily removes for washing. One year limited warranty.