This is the Safewedge. You may ask yourself what is the Safewedge. The Safewedge is
A wireless electronic Wedge Shaped Floor Metal Door Stop Alarm security device that can be used for Traveling, Office, Home, etc.

Stainless steel pressing plate is the basis of anti-theft protection and life safety, and durable pressure resistance is the key

The pressure sensitivity can be adjusted according to different conditions and there are 3 levels

The bottom has anti skid damping

This device has an alarm that activates when a door is opened and is putting pressure on the wedge which can alert you and let you know someone is there

Features and specs:
Equipment: door alarm
Function: 3 sensitivity levels
Size: 14cm x 4. 5cm x 4.0cm/5.5x1.7x1.57in
Material: abs+stainless steel
Power supply mode: 1 x 9V battery (not included)