Alarm lock with replaceable lock body

A lock comprising:

• a hollow cylindrical seat adapted to extend through a hole and comprising a stop plate at one end thereof, the stop plate having provided therein a pair of opposing outward recessive wedge and a pair of opposing stop recessions;
• a cylindrical lock body having a distal end and a proximal end and being adapted for insertion into the seat, the lock body having a longitudinally extending through bore, a pair of opposing ears being disposed on the exterior surface and near the distal end of the lock body, each ear having thereon a fixing recession for engaging the stop recessions in the seat, the exterior surface of the proximal end of the lock body being threaded, a cavity being provided on the exterior surface of the lock body to accommodate therein a ball;
• a screw hood adapted for screwing onto the proximal end of the lock body, the screw hood having a plurality of cavities on the interior surface thereof to accommodate the ball;
• and
• a cylindrical lock barrel for insertion into the lock body, the lock barrel having conical recession for accommodating the ball to permit removal of the lock barrel and for pushing the ball into the cavity in the screw hood to thereby prevent removal of the lock barrel from the lock body.