In The Swim 16-Year 20 x 40 ft. Rectangle Pool Winter Cover with Right Step Section Features "Rip Stop" material that prevents a puncture from becoming a tear All seams are heat-sealed (not sewn) to prevent water from seeping through the cover Resistant to algae growth, mold, mildew, and common pool chemicals Water tubes not included Step section determined by standing in the shallow end looking towards the deep end