Wireless Chime (AC Receiver + Push Button Transmitter x 2) You can use it immediately with one transmitter set by plugging the receiver into an outlet. You can also use the spare transmitter by setting it up for expansion, allowing it to play the same sound as the set transmitter, or you can set it to a different sound. In my case, I used it with a set of one transmitter for my mother's care in the separate buildings of adjacent wooden houses, on the 1st and 2nd floors (the other transmitter was purchased at the same time as a spare but was unused). [Please note that there is no call function at all.] <The box will be folded and shipped> Please refrain from purchasing if you are sensitive to this. NCNR (No Claim, No Return) <Specifications> Body size: Receiver/approx. W55 x D45 x H110mm, Transmitter/approx. W48 x D20 x H85mm Weight: Receiver/approx. 62g, Transmitter/approx. 36g Volume: 25db to maximum 100db (5-level volume adjustment) Power consumption: 0.8W Radio wave reach distance: Up to approx. 50m *The radio wave reach distance is a theoretical value. The distance varies depending on the situation and environment. Frequency: 426MHz (specified low-power equipment) Operating environment temperature: 0℃ to 40℃ Number of transmitter connections: 2 / (maximum 20) Receiver: Power supply is a flat plug direct insertion specification (PSE certified) Accessories: Transmitter double-sided tape plate (unused), Japanese instruction manual <Caution> This product can be used at a line-of-sight distance of approximately 50m if there are no obstacles, but the radio waves may be difficult to reach and may not be usable in the following cases: 1. When there are many walls and doors between the devices. 2. When used in buildings using reinforced concrete and steel frames. 3. When used between different floors or different buildings. 4. Obstacles (concrete walls, metal exterior walls, walls with insulation materials, metal furniture and doors, metal doors and shutters) This is a wireless chime that sounds when the call button is pressed. It can be used not only as a doorbell for the entrance (can be mounted on the wall using the included double-sided tape plate), but also as a call bell for shops and offices, and as a call bell for nursing care. You can use it just by plugging the receiver directly into an outlet, so no construction work such as drilling holes in the wall is required! Transmitter: Generates power by pressing the button No battery replacement required and maintenance-free! You can adjust the volume in 5 levels by pressing the volume button on the receiver. You can set it to a maximum of 100db, so it is also ideal for installation in places where it is difficult to hear. 52 call sounds You can change it to your liking.