4" O.D. Filters - 4CH-21DF4" O.D. Filters - 4CH-21DFAvailability: 10 in stockSKU: 4CH-21DFManufacturer part number: 4CH-21DF $14.48 Qty: Add to cart Custom wishlist OKAdd to wishlistAdd to compare listEmail a friendPart Number / SKU: 4CH-21DFProduct: 4" O.D. Filters - 4CH-21DFCategory: Filter Cartridges >> 4" O.D. FiltersProduct tags hot tub parts (7713), 4CH-21DF (1)