ZZ35

Early war mine / booby trap fuse. A detonator would be placed inside the fuse well and then secured inside a mine or explosive.

Will need a 3/4" key ring around the pin to complete the look.

Would be armed either by securing a trip wire around the key ring and then removing the safety nut, or tying the wire around the top hole and removing the pin, so that any soldier that cuts the wire would allow the striker to plunge and ignite the mine.