The doorbell can use in office,home, hospital,factory,restaurant or any where you need it. The receiver unit can be free standing or wall mounted using the included hardware. Install the push button with provided double sided tape or screw it to the wall (screws are included). 300 meter receiving distance (In the open area),Stable quality is Perfect for villas, hotels, schools and other areas. The button cannot be placed on an iron door because it will interfere with the signal. Doorbell model: A06 Operating range:300 meters in open area Volume:4 levels Ringtones:36 pcs Transmitter size:77*46*20mm Receiver size:95*65*24mm Transmitter battery type: 12 V 23A alkaline battery (battery not included) Receiver battery type: 3*AA batteries (battery not included) Waterproof grade: IP44 Colour: Black material: plastic Package Content: 1* Doorbell Launcher 1* doorbell receiver 1* battery 1* screw 1* double-sided tape Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.