Evelots DIY Wireless Door & Window Security Alarms, Entrance Alerts, White- S/2 This set of 2 wireless window alarms/door bells are great for "do-it-yourself" residential and commercial applications. Convenient, no-tools installation. Quick set up and easy to use. Each alarm measures approximately 2.5"L by 1.75"W by .75"H with both pieces combined. Can also be used on cabinets that have hazardous cleaning supplies for babies to alert you when they have been opened. Comes with a total of 2 white wireless door/window alarms. Made out of durable white plastic that will go with just about any decor! Trusted vendor. For years Evelots has provided unique products with a 30 day easy return policy, and 100% satisfaction guarantee.