Strong Suction: Made of soft and flexible resin material, the suction cups can sticky tightly to your fish tank, aquarium or other glass for stable holding For Standard Heaters: Each suction cup 1.38" in diameter with a 0.95" clip. Perfect for holding standard aquarium heaters, tubing or rain bars; Easy Maintenance: Just clean and dry both suction cups and glass before installation Tough Clips: Each suction cup comes with a clip. sturdy enough to firmly keep your aquarium heater in place Description: