Packing a powerful punch in a compact size, the Flipo 2-in-1 Door & Personal Alarm System emits an ear-piercing sound for portable protection. This is a dual-purpose alarm; acting as a door alarm or portable personal alarm. To use as a door alarm hang device onto any non-metallic doors doorknob, then switch to “ON” position. The alarm will be activated 15-20 seconds after being hung. Once activated the alarm will automatically sound whenever the exterior doorknob is in contact with a human touch. Or, carry the alarm with you for portable protection as a personal alarm. To use as a personal alarm, switch the alarm to the “OFF” position. Activate the ear-piercing alarm sound by pulling out the metal chain from the alarm unit. The alarm will sound until the metal chain is reinserted. Each alarm requires one 9-volt alkaline battery (not included).