Abstract: In the preferred and illustrated embodiment, a protective anti-theft device for installation on a fireplug is shown. In the preferred and illustrated embodiment, a nut suitable for installation on a fireplug is provided, the nut having an external groove to receive a snap ring therein. A sleeve is joined to the nut by means of a cooperative groove receiving the snap ring therein. This enables the sleeve to free wheel around the nut. The free wheeling sleeve prevents theft and pilferage of the nut once it is installed on a fireplug at the top end to support the stem in the fireplug.

Abstract: A lock and coupling apparatus for securing fire hydrants is disclosed. The two piece apparatus comprises an inner member concentrically received within an outer cylindrical member. The inner member is formed with a socket for receiving the five sided hydrant valve post. A snap ring connects the outer member to the inner member while permitting rotational movement therebetween. A square lock pin moveable between locked and unlocked positions is provided to lock the inner and outer members so that rotational movement of the outer member is transmitted to the inner member. A specifically designed wrench for imparting rotary movement to the outer member is also disclosed.