4 Pack Safe Home Loud Siren Wireless Door or Window Alarm Security Safety System 90db - Easy to Install (1.5"x 2") - Loud Siren Security for Home, Apartment and Office, Package and Product Designed in Usa, Home Protection Unit Set of 4 alarms 7/24 reliable and excellent quality designed in the USA Provides alarm security for doors, windows, sliding glass doors and cabinets (not for horizontal window opening) Alarm sounds when magnetic contact is separated Ultra loud alarm, Easy to install, no wiring Don't wait til break-ins to take care of matter