Spin Clean Filter. Y filter made of chemical resistant glass-reinforced plastic. Water spins thru and deposits debris at the bottom of the filter which can be cleaned by opening a ball valve. 150 mesh stainless steel screen is standard. Male pipe thread fittings. Warning: do not install this filter where it will be under constant pressure or the unit may crack. 3/4" filter max flow 9 gpm. 1" filter max flow 18 gpm. Both the 3/4" unit and the 1" unit (purchased after Jan 2003) use replacement screens that are 5.25" long.