Oil-absorbing sponge absorbs 40 times its weight in body oils and suntan lotions. Also loves pollen. Improves filtration and, when placed in a clean pool or spa, it helps to eliminate the formation of a scum line. Cannot get clogged in water lines. Simply place Scumbug in pool skimmer (fits all) or free-float in spa. When one side is scummy, flip it over. When saturated, squeeze out, clean and reuse. Under normal conditions, Scumbug should last an average swimming season.