Sticky Pod Suction Cup Strong, Heavy Duty, Industrial Suction Cup with a Performance Guarantee 3-1/8 Inches (uncompressed), 3-3/8 Inches (compressed), 1/4-20 Nut Hard Molded Inside Sticky Pod Suction Cups Typically Stay In Place For Over 1 Year Each Cup Has Approximately 40 Pounds of Grip Force Great For Kayaks, Boats, Cars, RVs, Campers, Trucks, Surfboards, Paddleboards, Canoes, Helmets