ANTI-THEFT DEVICE

摘要

An anti-theft device for mounting an object to a base, said device comprising a nut or a bolt and a key, said nut or bolt comprising a rotatable member having a screw threaded portion (1a) inter-engageable with a threaded portion on the base and having a drive portion (2) adapted to engage with the key (4), said device further comprising a rotatable sleeve (3) extending substantially around the periphery of the drive portion, a clearance fit gap separating the sleeve and the drive portion, characterised in that the clearance fit gap has a stepped or non-linear configuration when viewed in cross-section, thus preventing a tool being driven directly into the gap between the drive portion and the sleeve.