Uni UP-4200ST Clamp-On Dual Layer"Pod" Filter Uni Clamp-On Dual Layer Pod Air Filter - Straight Please see our Warranty & Returns Policy. Item Number: UP-4200ST Straight Dual Layer (2 Stage Black Inner, Red Outer) Urethane Flange Inner Diameter: 2 inches (50.8mm) Outer Diameter: 3.5 inches (88.9mm) Length: 4 inches (102mm) Made in U.S.A.