These 3/8" NPT male pipe plugs are engineered with a Vibra-Seal coating, providing excellent resistance to leaks and vibrations. Designed for automotive engines, including L4, L6, V6, and V8 configurations, these plugs ensure a secure, airtight seal. Manufactured in the USA with premium zinc plated steel, the pack of 10 plugs offers both durability and easy installation with their hex head design. Ideal for high-vibration environments, these plugs are trusted by professionals for reliable engine maintenance. Enginequest has inventory in many different sizes of plugs. NPT, Metric and Japanese thread.