Sparkplug holder for CR8E and similar sized sparkplugs. Protects the spark gap and the ceramic body when in your tool box or tool tube for dirt/adventure riding.
Should have slight interference fit at 100% scale. If not there's a little free play so you can scale up or down one of the halves by 1% to get a friction fit and probably not have a problem getting the spark plug in.
used fusion 360. file included if you want to modify.