swimline s1834ov 18 foot x 34 foot deluxe above ground swimming pool winter cover swimline the deluxe 18' x 34' winter pool cover is made of extra strong polyethylene sheeting woven with thick polyethylene stitching, which provides superior strength and durability.adding a deluxe oval winter cover will protect your pool from the harsher elements of winter and keeps debris, algae and bacteria out of the water, minimizing maintenance when re-opening the pool in spring. safeguard your pool to ensure years of backyard enjoyment and family fun.the polarshield deluxe winter pool cover includes an extended 10 year limited warranty, with 2 year full coverage. view the attached warranty for more detailed information.