Plug Type: US Plug, compatible with Canada, Japan, Mexico, Thailand, the Philippines, and other countries. Unique and elegant design Transmitter powered by solar energy, energy-saving and durable Range in open spaces: up to 200-300m 52 selectable ringtones; one transmitter can pair with multiple receivers Ringtones: 52 Color: Black Material: ABS 4-level adjustable volume, including silent mode One transmitter can pair with multiple receivers; one receiver can pair with multiple transmitters Expandable system add additional transmitters or receivers To pair: plug into socket, press volume button for 6 seconds until blue LED stays on, then press transmitter button; when receivers blue LED flashes, pairing is successful Pairing will fail if not completed within 6 seconds Note: Supports multiple pairings between transmitters and receivers, with power-off memory function Transmitter specifications: - Solar cell powered - Operating reference: 5.5V 25mA 0.13W - No code string required - Working current: 12mA - Response time: 0.5 seconds with LED indicator when button is pressed - Operating range: approximately 200-300m (in open air) Receiver specifications: - Operating voltage: 90-260V - Standby current: 10mA - Working current: 60mA - Operating frequency: 433MHz - Built-in night light function, automatically illuminates in low-light conditions Package Contents: 1 x Indoor Unit (Receiver) 1 x Outdoor Unit (Transmitter) 1 x Mounting Base 1 x Bag of Screws 1 x Tape Only the items listed above are included; other accessories are not included Note: Lighting and display differences may cause slight color variations between the image and actual product. Measurement error allowance: +/- 1-3cm