The Techko S184S Ultra Slim Door Guard Alarm is a simple and effective solution that can provide protection of your valuables. The Techko S184S detects vibration from attempted door entry. Set up is easy, no tools required. Simply select the desired mode (alarm or chime) and hang the device on any door. The Techko S184S has an activation delay to allow time for setup. This device is portable and great during travel or in the home.