Boat Drink Cup Marine Beverage Holder, Clamp on, by Cuda's Customs Custom Clamp-on Marine Boat Drink Holder, Small Cup fits Bottle With Koozie, Large Cup fits Can With Foam Koozie or a 24 ounce Tervis Tumbler. Add no holes in your boat but more drink holders. Tough and durable part made of UV protected marine starboard and marine grade stainless allen head screws. Each holder Custom Made for All Sizes of Vertical Pipes on Your Boat. Rotates 360 degrees without damaging pipe beneath. Cup inserts are removable for cleaning and/or replacing.