Usage Tips:4 in 1 Mode: This alarm with 4 modes. 1. Timing alarm (sounds 'Di-Di-Di' from 0dB to 108dB if the door remains open for 3/15/30/60s) 2. General alarm (stop alarm if door closed); 3. Constant alarm (constant alarm even closed door); 4. Door Opening Chime (Sounds "DingDong" once door is opened) Loud 108dB Alarm: Door and window alarm helps effectively deter intruders/thieves with a loud alarm of 108 dB. You can easily set the suitable mode according to your needs. Easy to Install: Simple peel and stick installation, easy to install on most freezer/fridge or any door without any tools. package including 2 fridge alarms, 2 magnetic strips, double-sided sticker, user manual. Installation note: be sure to close the alarm and magnetic strip, distance of installation between them should not exceed 0.78 inch. The 2 parts must be aligned by their alignment arrow. 2 AA batteries can stay for 2 years. (Batteries are not included) Widely Used: Magnetic Trigger Door Alarm Sensor Protecting Home Through Door Window Entrance and Suitable for Safe, Cabinet, Freezers , refrigerators, swimming pool sliding door, shop, office, apartment, hotel, etc. Multi-use: 1. Fridge, refrigerator, freezer door alarm reminder 2. Window door alarm for home security 3. Cabinet Door Alarm in Shop Security Package including: 2 x Refrigerator Alarms 2 x Magnetic Stripe 2 x double-sided sticker 1 x user manual Battery operated, requires two AAA alkaline batteries (not included). It is a physical image. When the batteries are installed, the light will glow red. Low-power design: Low-power design, they can work for more than 2 years. Low battery warning, when batteries need to be replaced, the LED light will flash once per second.