This rail mounted cup holder's large size and versatile fastening allow it to securely fit on rail tubing from 0.625 to 1.25 inch (16 to 32 mm) diameter, and easily accommodate common can and bottle sizes up to 2.6” (66mm). Simple to install with just a screwdriver, this cup holder uses the same trusted rail mounting system as our boat fender holders, so putting them on is a breeze. The holders are made from high quality stainless steel components with a sturdy UV resistant nylon mounting bracket that will attach securely and stand up to challenging boating conditions. Made in Finland by NAWA registered trademark by Lankapaja Oy.