boulder swirl overlap 18 round wall 48 to 54 above ground pool linerOverlap liners hang over the top of the pool wall and are secured in place with coping strips before the top rails are reinstalled. This design is made for above ground pools with a flat, constant depth floor. This liner fits pools with walls up to 54 inches and can be stretched to a cove bottom up to 8 inches when installed in warm conditions. It is designed for specific pool sizes and is not intended for expandable bottom or deep end pools.