You are purchasing a set of (16) Viton Metal CladUNIVERSAL Valve Stem Seals.These seals will fit many different engines with the following guide and valvedimensions. Here are a few examples: Ford, Chevy, Dodge, Plymouth,Chrysler, Pontiac, Oldsmobile, Buick, GM, Mopar.Specifications:3/8 Fitted Stem Size / Diameter.625 Fitted Guide Size / Diameter.744 Width.526 HeightPositive Metal Clad BodySupreme FKMMetal Clad Body w/ Rubber Inside Skirt and Garter Spring at Chimney Valve stem seals are purchased in bulk and repackaged insets of (16). You will be sent a set of (16) 3/8 X .625 PositiveMetal Clad valve stem seals.