4 in 1 Multifunction: 4 modes to meet your different needs: general alarm, constant alarm, time delay (closing alarm) and doorbell, just press the button to select the function you need without any complicated settings. This contact sensor set can quickly detect the status of your door or window. Requires 2 AAA batteries (not included).

Freezer Door Alarm with Delay and Wide Range of Use: Upgraded versions with 3/15/30/60 seconds delay to choose from. Magnetic trigger door alarm sensor that protects the home through windows, front door, suitable for safes, cabinets, freezer, refrigerator, sliding door, store, office, apartment, hotel, etc.

108dB Loud Enough for Your Home Security: The door and window alarm helps deter intruders and thieves effectively with a loud 108dB alarm, even the open signal will alert you if children/pets/elderly come or go unexpectedly. It can prevent your children from sneaking around. And it is a perfect wireless security magnetic alarm for child safety, burglary, home, garage, mailbox and business security.

Easy to Install: This home/window contact sensor alarm kit comes with self-adhesive pads so no tools are needed, just attach the door alarm sensor to the door or window. It can also be used as a door stop alarm, pool door alarm, garage door alarm or sliding door alarm. Low power design, provides practical and long-term protection. They can work for more than 2 years.

Installation Note: Make sure to close the alarm and magnetic strip, the installation distance between them must not exceed 2 cm. The two parts must be aligned with their alignment arrow.