Compression Test Extension: H

7881 Compression Test Extension Features and Benefits: The spark plug hole extension enables you to extend a spark plug hole above the valve cover on hemi and deep-plug-hole engines Works deep-hole pings and hemi engines Extends spark plug hole 7.5 inches Attach compression gauges easily 14mm thread diameter Steel 1144 alloy 8" Length O-Ring seal allows complete compression transfer Lifetime Warranty