Marine Grade Stainless Double Ring Cup Drink Holder - open design Double Stainless Drink Holder is cast from solid marine-grade 316 stainless. Double drink holders are designed to fit Koozies, cans, mugs and large cups up to 3-3/8” in diameter. The elegant design also features an open frame to accommodate coffee cup handles. The drink holders sit 3” high when installed and are highly polished.