Abstract: An improved anti-theft locking device permanently and quickly securable to various objects by self-contained concealed fastener means sized to have an interference locking fit with a mounting bore such as the interior of a cycle handlebar or the like. The locking bolt may be secured to one end of a flexible cable normally stored and concealed in the handlebar and the major length of which is withdrawable therefrom when used to lash the cycle to a fixed object. The outer end of the cable is fixed to the locking bolt and this bolt is invertable so that either end is insertable into the locking mechanism depending upon whether or not the cable is in use. A variant embodiment of the invention is readily installed between a door and its casing and may utilize a linkage in lieu of a flexible cable as a part of the anchor subassembly.