Abstract: This invention is an alarm lock which uses a key-releasable cable to secure an article to be protected to a fixed object. Should the cable be cut, a coded audio alarm is emitted, alerting the owner of the article. The cable contains a conductor which is connected to an alarm circuit sensitive to a resistance in series with the cable. Attempts to defeat the cable by jumpering or cutting or otherwise varying the resistance causes the alarm to be set off. Pulling the cable (tampering) also causes the alarm to operate, for a fixed period of time. The lock unit can be fixed to the handle bars of a bicycle and the alarm sound can be generated manually whereby it can be used as a horn.