Enhance your home security and convenience with this reliable Wireless Doorbell system, designed to meet national frequency regulations and ensure no harmful electromagnetic interference. Crafted from durable ABS plastic, this doorbell kit includes an outdoor machine powered by 4 AAA batteries (not included), and an indoor machine that operates via USB connection, providing a practical and user-friendly solution for your door alert needs. Key Features: · Compliant Frequency & Safe Operation: Operates at 467.6375 MHz frequency in accordance with national standards, guaranteeing no harmful electromagnetic interference for safe usage. · Outdoor Machine Powered by 4 AAA Batteries: Easy battery installation and replacement with a battery life of up to four months, ensuring long-lasting and reliable performance. Battery not included. · Indoor Machine USB Powered: No need for batteries in the indoor unit, powered conveniently via a 5V 1A USB connection for continuous operation without battery worry. · Adjustable Volume & Changeable Ringtones: Customize the doorbell sound to your preference with multiple ringtone options and adjustable volume control, delivering clear, loud, and pleasant sound. · Simple & Quick Installation: Easily mount the outdoor unit using adhesive tape for hassle-free setup with minimal time and effort. · Learning Code Technology: One outdoor machine can pair with multiple indoor units without interference, providing wireless flexibility across your home. · Suitable Working Conditions: Designed to work effectively within temperatures ranging from -20°C to 55°C, adaptable for various environments. · Transmission Range: Reliable wireless signal with an approximate range of 200 meters (218 yards) in open areas and 5 to 50 meters (16.4 to 164 yards) through obstacles, ensuring dependable communication between units. Specifications: Material: ABS Plastic Color: As Picture Shown Outdoor Machine: - Battery: 4 x AAA batteries (not included) - Working Frequency: 467.6375 MHz - Working Temperature: -20 to 55°C - Transmission Distance: Approx. 200m (open place), 5-50m (with obstacles) - Waterproof Rating: No waterproof function Indoor Machine: - Voltage Range: 5V 1A via USB - Working Frequency: 467.6375 MHz - Working Temperature: -20 to 55°C - Transmission Distance: Approx. 200m (open place), 5-50m (with obstacles) - Waterproof Rating: No waterproof function Package Includes: 1 x Outdoor Doorbell Unit 1 x Indoor Doorbell Unit This Wireless Doorbell offers a seamless blend of convenience, safety, and ease of use, making it an ideal choice for homeowners seeking an effective door alert system with simple installation and flexible indoor integration.