RAM Mounts Suction Cup Base Features Made of High Strength Composite and Powder Coated Marine Grade Aluminum material Equipped with a 3.3 diameter suction cup twist lock base that connects to the 222-240 diamond base with a 1 rubber ball, B size Created to ensure a secure grip on any smooth non-porous surface For best results, suction cup should be mounted on a glass or non-porous plastic surface