You get 4 pieces that will work on 4 doors or windows. Just peel and stick in install.

• Feel Safe and Secure Affordably
• Magnet-activated alarms self-adhere instantly to doors, windows, and cabinets, sounding a 90-decibel alarm upon opening
• On/off switch deactivates alarm
• Requires 3 AG13 batteries (included and pre-installed)
• Great for caregivers
• Set of 4, each 2 1/2" x 1 3/4" x 3/4"