Description Supertech high precision valve stem seal, formulated specifically for intake valve use. This valve stem seal is suitable for use with 7mm valve stems, as found in many BMW engines – M20, early M50, M70, M73, S14, S38, S50B30, S70 and more. These will also fit many other applications including VAG. Guide OD 9.8mm, Seal OD 13.2mm. Priced per seal.