Info: Wireless Doorbell Button and Plug-In Receiver
If you're frequently in a room too far away to hear someone knocking at the door, or live in a suite without a doorbell, or simply need to replace or install a doorbell, this is the perfect device for you. Augreener's Wireless Doorbell works somewhat like a Bluetooth device: pressing the doorbell button transmits a signal to the receiver unit inside, which you plug into a regular outlet in whichever room you'd like to hear it, up to 70 meters away. Best of all, the button doesn't require any power -- not even a battery!
The button can attached by screwing in the mounting plate it snaps onto, or it can easily be mounted with its own adhesive pad (albeit not on UPVC door frames, or near metal surfaces, which can interfere with its range), and it's quite weatherproof: it can handle the sun and the rain, and works well from as cold as -40C/F to as hot as +60C/140F. You can even change the type of chime you prefer by pressing the button on the receiver (which has a ring of blue LED light when powered).
46 x 88 x 32mm (Doorbell Button)
68 x 86 x 71mm (Receiver)
Download the Augreener - Battery-Free Wireless Doorbell Manual [PDF]