KPMI, intake/exhaust valve guide. Cast iron. +.008"

Cast iron is great when it comes to maximum durability and wear resistance. It is perfect for long distance touring applications. It is the standard since the invention of the piston engine. Note: Standard non-oversize dimensions (for reference only) are 0.6440" O.D. (16.37mm); 1.050" I.D. (26.67mm); 1.900" OAL (48.26mm).

Fits: > 36-47 Knucklehead (NU)