Abstract: A portable tamperproof and battery-powered alarm device used for locking in place, objects which need to be restrained from theft. The device is ideal for locking bicycles, mini-bikes, motor cycles, and the like, due to its portability and versatility. The device includes a casing for an alarm and operative circuit therefor and an object-restraining member. Once the device is activated by an internal switch, any interruptions of the circuit, such as breaking of the restraining member, cause an audible alarm to sound continuously until the device is manually reset. The locking and alarm device is a completely separate unit from the object-restraining member, and thus the latter may be readily replaced as needed.