This is a battery-free, self-generating wireless chime. The transmitter generates power simply by being pressed, eliminating the need for battery replacement and offering long-lasting usability. The receiver can be used by simply plugging it into an outlet, requiring no installation. The volume is adjustable in 7 levels. It notifies you not only with sound but also with LED light when a visitor arrives, making it easy to notice even in noisy environments or situations where it's difficult to hear. There are over 60 melodies to choose from, allowing you to select your preferred one. The wireless communication range is wide, suitable for apartments, detached houses, as well as restaurants and nursing care facilities. It's waterproof and dustproof, so it can be used outdoors, such as at the entrance, with peace of mind. It has a memory function that remembers the settings, so there's no need to reset it even if the power is unplugged. This is a new, unused item, only opened once for photography. Although it has not been used, there may be minor scratches due to being a foreign product. This is a set of 1 transmitter and 1 receiver.