The boat cup holders are made of ABS plastic, the cup holder clips have anti-rubber, strong grip, mount to the boat rail, the adjustable knob will make the cup holder rock solid on the rail, you can put drinks in these cup holders Don't worry about spilling all over the place. The cup holders are easy to install, just clamp and move, no tools and components required, no drilling required, no damage to the boat, mounts on boat aluminum rails, poles or bimini top rails. The boat shaped drink holder is simple, unique, durable and practical, and the designed cup holder can accommodate bottles of different sizes. The adjustable clip allows for swivel and can be used for horizontal poles or any inclined poles, not just vertical. So it can be installed at different angles. The anti-rubber keeps the inside in place, preventing drinks from spilling and falling off pontoon boats, bass boats, jon boats, jets. The boat rail cup holder holds water bottles, coffee mugs, beer, cans, glasses and more. Mounts to the rails on your boat and the cup holders can be moved to any rail. Ideal for yachts, pontoon boats, bass boats, jon boats, kayaks and soon. The interior of the universal drink holder is roomy for odds and ends. Sunscreen, fish tongs, drinks, hand towels, bait, some small trash, etc. Color: Black: ABS Package Contents: 1 Cup Holder Only the above package content, other products are not included. Note: Light reflections and different monitors may cause the item's color to be slightly different from the real item. The measurement allowable error is +/-1-3cm.