MOTION-ACTIVATED ALARM With KEYPAD. Wireless security system detects movement across a 20 ft. x 110 ft. zone; its piercing 120 dB siren can be heard up to 750 ft. away. Can also be set to chime to announce visitors. Has a 4-digit keypad for your custom code plus entry and exit delay modes. Includes mounting hardware. Uses 3 AAA batteries (not incl.). 5¼" x 2½" x 1½".