Boat Cup Holder Universal Clamp on by Cuda's Customs Made of Marine grade UV protected starboard and 4 stainless screws. Very strong, durable part made to be long lasting. Attractive drink holder. Comes in a small cup size that fits a bottle with a koozie. Comes in a big cup size that fits a can with a foam koozie and even a 24 oz. Tervis Tumbler.