Boat Cup holder, rail mount. Made from UV resistant ASA plastic, great for marine environments. Comes with adjustable mounting hardware to mount to round rail tubing from 7/8" to 1" in diameter. Can be mounted at almost any angle, from vertical to horizontal rails. Can also be directly attached to a wall or fiberglass portion of boat using stainless steel flat head wood screws(not included.) Can hold cups and bottles up to 3inches in diameter.