SeaSuckers are Vacuum Cup Mounts, not suction cups. There’s a big difference between the two. Our vacuum cups have enormous holding power and will stay attached to a smooth flat surface for days at a time. The 114mm (4 1/2″) SeaSucker is rated to hold over 45Kg’s (100lbs) !  If you think that’s strong, our 152mm (6″) SeaSucker will hold over 90Kg’s