One-button control: This alarm bell does not require an additional remote control. It has a built-in on/off button and a setup button to adjust the volume and mode. Five modes: press the setting button once to activate the alarm mode; press the setting button twice to activate the doorbell mode; press the setting button three times to activate the 30-second alarm; press the setting button four times to activate the buzzer alarm; press the setting button five times to activate the 15-second alarm. Parameters: Built-in 3 LR44 batteries, dimensions: 65 x 34 x 16.5 mm.