The doorbell can use in office,home, hospital,factory,restaurant or any where you need it.The receiver unit can be free standing or 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: A06Operating range:300 meters in open areaVolume:4 levelsRingtones:36 pcsTransmitter size:77*46*20mmReceiver size:95*65*24mmTransmitter battery type: 12 V 23A alkaline battery (battery not included)Receiver battery type: 3*AA batteries (battery not included)Waterproof grade: IP44Colour: Blackmaterial: plasticPackage Content: 1* Doorbell Launcher1* doorbell receiver1* battery1* screw1* double-sided tapeOnly 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.