This Graco teflon o-ring is placed on the inlet valve and helps create a seal between the ball, cage, and piston valve. This o-ring is used on a variety of Graco's airless paint sprayers; including the 390 Duron, Husky 307, the Gmax 7900 and various others.
Part #: 117559
Part #: 115099
Part #: 117828
Part #: 114049