The Fish Fighter Sure-Grip Extreme™ Drink holder was designed to hold your drink securely in all waters. This is no cheapo drink holder. This bad boy was designed to last for generations and to work as advertised. We made the body out of marine-grade aluminum then powder coated it in our tuff coat finish. Then we install our Sure Grip™ Tension Springs. These Sure Grip Springs were designed by us to grip a wide range of drinks and cups and not let go unless you pull the drink straight up. In shorts we designed and Extreme Drink Holder for those of you who go out in all weather and all conditions. This Drink Holder has pre-cut holes to mount directly to any flat or vertical surface.