Practical｜ Other Products ｜Door Knock Sensor Transmitter CA-DXH

You can easily attach the Door Knocking Sensor (Model CA-DX, sold separately) to this hanger and hang it on your door knob to detect the knocking on your door. The CA-DX sensor sends a wireless signal to trigger the CA-360 to alert you that someone is at the door. Ideal for both home and hotel stay applications.
Product Specifications: 
Operating Frequency: 2.4 Ghz Operating Range: Up to 210 ft, open space Battery Type: Two AA size alkaline (not included) Battery Life: Up to 10 months Size: 2.5” x 3.8” x 1” - Net Wt: 4 Oz
Brand:Serene InnovationsSKU:7215-DXHTags:Serene Innovations - CentralAlert, Signaling & Notification