12'x20'x4' Rectangle Beaded Caribbean Above Ground Swimming Pool Liner-20 Gauge MEASURE TWICE, BUY ONCE  Whether installing for the first time, or replacing an existing liner, the Caribbean pattern offers durability while not breaking the bank. Be sure to check the measurements of your swimming pool to assure the correct size is purchased. Pool height is determined by measuring the outside wall from the ground to underneath the top rail. Round pool size is determined by measuring from the center point wall to wall in order to obtain the diameter. PRETTY PLEASING PATTERN - The Caribbean pattern gives a delightful depiction of exotic fish swimming around your pool. The North American cut material is hand-folded to prevent permanent creasing and excess wrinkling. Before installing, lay the liner out in the sun for a minimum of one hour to warm up the vinyl ensuring it is able to stretch when adding water. The best temperatures to install would be between 70-80 degrees. STAY COOL IN THE POOL  Enjoy the warm weather while spending quality time with family and friends. Your backyard aboveground pool will surely become the place to be during those hot summer days. Stay cool in more ways than one with the Caribbean liner. HIGH QUALITY MATERIAL - Swim care-free knowing your liner can tough it out through abrasion, chemicals and UV fading thanks to the use of Lamiclear technology. The layers are made of an acrylic top coat, a UV resistant print layer, and a 100% virgin vinyl base. This material is then welded and cut for a flawless fit and finish. A 25-year limited warranty is included protecting against defects in material and workmanship.