Jandy Pro Series SFTM22 22 1/2" SFTM Top Mount Sand Filter directs water evenly across the entire surface of sand without sand migration or channeling. Top-mount pool sand filters contain an extra deep sand bed for improved filtration. Its blow-molded tank is corrosion and UV-resistant with a bottom drain that’s ideal for winterizing and draining. It also includes a 7-way dial valve with sight glass, automatic air relief and pressure gauge. The SFTM has a non-corrosive resin clamp that allows 360 degree rotation of the dial valve for simple installation, alignment, and service of dial valve and filter components. A heavy-duty, freeze-resistant under-drain with "snap-fit" side slotted laterals draws water evenly across the full diameter of the sand bed (up to 25 gpm/sq.ft.) Perfect for higher flows, better filtration, longer cycles and more efficient backwashing.