Plug Type: US Plug, compatible with Canada, Japan, Mexico, Thailand, the Philippines, and other countries with standard US outlets. Unique and elegant design Transmitter powered by solar energy, energy-saving and durable Range in open areas: up to 200-300 meters 52 selectable melodies; one transmitter can pair with multiple receivers Ringtones: 52 Color: Black Material: ABS 4 adjustable volume levels, including silent mode One transmitter can pair with multiple receivers; one receiver can pair with multiple transmitters To pair: Plug in the transmitter or receiver, press and hold the volume button for 6 seconds until the blue LED stays on, then press the transmitter button. When the receiver’s blue LED flashes, pairing is successful Pairing will fail if not completed within 6 seconds Note: One transmitter can pair with multiple receivers; one receiver can pair with multiple transmitters. Device retains memory after power off Transmitter: Solar panel powered Operating reference: 5.5V 25mA 0.13W No code required Operating current: 12mA Response time: 0.5 seconds with light indicator when button is pressed Operating range: approximately 200-300 meters (in open air) Receiver: Operating voltage: 90-260V Standby current: 10mA Operating 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 the actual item. Measurement error allowance: +/- 1-3 cm