This convenient and cost-effective wireless chime set includes two receivers and one transmitter. The transmitter is self-powered by the force of being pressed, eliminating the need for battery replacement or wiring. It can be installed anywhere and is widely used at entrances, nursing care facilities, and more. 【Clear Notification with Light & Sound】 The high-sensitivity receiver achieves a communication distance of up to 150m (over 30m through walls). It can be used stably even in large houses. There are 32 call melodies and 4 volume levels. The sound and light notification is designed to be user-friendly for those with visual or hearing impairments. There are 3 operation modes: "Sound + Light", "Sound Only", and "Light Only (Silent)". Switching is easy by simultaneously pressing and holding the volume button and the song selection button. 【Interference Prevention & IP44 Waterproof】 The transmitter is designed to be less susceptible to interference, ensuring stable wireless communication. The IP44 waterproof design allows it to be used outdoors at entrances or near bathrooms. 【Wireless & No Wiring Required】 Simply plug the receiver into an outlet. The transmitter requires no batteries or power and can be easily installed with double-sided tape. No wiring is required, so it can be used immediately anywhere. 【Shape Options】 This product is available in two types: "Rectangular Type" and "Round Type". Please select your desired shape when ordering.