Enhance your home or office security with this Wireless USB Doorbell, designed for easy, wire-free installation and reliable performance. Featuring a professional waterproof design, this doorbell system ensures durability and functionality in various environments. With a strong signal capable of penetrating 3-4 walls and a range of up to 150 meters in open areas, it delivers consistent and stable connectivity for seamless use. Key Features: · Wire-Free and Plug-and-Play: Simple setup with no wiring required, making installation quick and hassle-free. · Long-Range Signal Penetration: Effectively transmits through 3-4 walls with a maximum range of 150 meters in open spaces, ensuring reliable operation across large homes, offices, or commercial spaces. · Customizable Sound Options: Offers 38 different music tones and 3-level volume adjustment, allowing you to personalize your doorbell chime to suit your preferences and environment. · Anti-Interference Technology: Designed to prevent false ringing and signal interference, providing dependable performance and peace of mind. · Professional Waterproof Design: Built to withstand various weather conditions, suitable for indoor and outdoor use in locations such as villas, apartments, offices, shops, and warehouses. Specifications: · Color: White · Working Voltage: 5V (USB powered) · Power Consumption: ≤0.25W · Working Frequency: 433.92 MHz · Operating Temperature: -10°C to +45°C · Controllable Volume: ≥50dB/1m · Remote Control Distance: ≥150 meters (unobstructed open space) · Transmitter Battery Model: CR2032 · Transmitter Power Consumption: <10mW · USB Interface Receiver Size: 43 x 41 x 32 mm (1.7 x 1.6 x 1.3 in) · Transmitter Size: 77 x 45 x 16 mm (3 x 1.8 x 0.6 in) · Package Size: 130 x 110 x 50 mm (5.1 x 4.3 x 2 in) · Package Weight:  - 1 Receiver 1 Doorbell: 78g (2.8oz)  - 1 Receiver 2 Doorbell: 105g (3.7oz) Package Includes: · Receiver(s) and Doorbell(s) as per your selection This Wireless USB Doorbell combines convenience, durability, and customization to provide a reliable and user-friendly alert system suitable for a variety of residential and commercial settings. Its waterproof construction and long-range capability make it an ideal choice for maintaining security and communication across multiple rooms and buildings.