Strong suction cups: The cat window suction cups can be applied to smooth surfaces, such as tiles, glass, etc., which have strong suction and can support your cat window bed well</ p> Sturdy & Long Lifespan: The cat hammock suction cups are made of quality PVC plastic, with smooth surface, safe and sturdy, which are easy to stick on walls and windows without leaving residue , and can be applied for a long time Extensive Uses: Replacement suction cups for cat window bed are suitable for hanging ropes, wires, plastic rods and iron chains, and also can be applied to hang cat window hammock, cat window perch, cat window seat, cat window bed and more. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Sold by-dadangjia