These plastic drink holders have adjustable spring loaded arms (stainless steel spring) to firmly grip various size cans, bottles and glasses from 65 – 80mm diameter. They are designed to mount permanently to any vertical surface as they simply fold up near flat after use – protrudes only 23mm when folded up. Manufactured from ABS plastic with a stainless steel spring. Mounting base size : 97 x 97mm Fastening holes: 4 x 5mm C/S. Protrudes Out : 23mm when closed – 102mm when open. Holds items from 65mm to 80mm diameter. -a must for any boater.