PREVENT UNWANTED INTRUDERS: 130dB will startle the intruder and alert you of suspicious activities. Parents also use this to keep their kids safe as well as to prevent people with Dementia or Alzheimers from going where they're not suppose to go | SIMPLE AND QUICK SETUP: No complex set up and wiring, the simple arm and disarm feature allows you to utilize one of two alarm modes (30 sec and continuous) and choose between sensitivity adjustment | COMPACT AND PORTABLE: Use as home security, apartment security, in your bedroom sensor, or on your travels while staying at a hotel | SECURE YOUR HOME: Vibration door alarm works on any type of doorknobs, including metal, French, standard, and plastic doorknobs | PACKAGE CONTENTS: 2x Vibration Detection Alarms, 2x 9V Batteries, Mounting dry wall screw (for mounting on wall), User's guide