Imperial Pools 0411048 4' Plain Panel with 1 Stiffener - Imperial uses a two-polymer approach for unlimited flexibility, allowing you to create a pool that is uniquely yours. The options are as boundless as your own imagination! Our Straight Walls and Fixed-Radius Panels are made of high-impact material and built to be the strongest in the industry. Our Versa Flex Radius Panels are made of a lightweight and resilient polymer and form to any desired shape you have for your pool.