2 pieces of O-ring fits all Spring Oasis Big Blue Housings and many other brands.Compatible with most 10" & 20" Big Blue Housings that take 3/16" x 5 5/8" O rings.
Note: This O ring does not fit our Big Fat Clear housings. For Big Fat Clear housing, use O rings of eBay item #222307161414Check your housing to make sure it is the same size as ours before purchase.