Feature 1: Wide Application – Wireless intercom doorbells are suitable for homes, hotels, villas, factories, and hospitals. Feature 2: Wireless Range – The barrier-free wireless range is up to 1,000 meters. No internet or wiring required—ready to use out of the box. Feature 3: Intelligent Design – Features LED indicators for intercom status and power, enabling clear, intuitive operation. Feature 4: Battery Life – Both outdoor and indoor units are powered by built-in 2000mAh rechargeable lithium batteries. With average usage (5 presses per day, 2 minutes of talk time each), the outdoor unit lasts approximately 8 months; the indoor unit lasts about 1 week. Feature 5: Advanced Chip – Equipped with a dedicated intelligent intercom chip offering strong signal penetration, supporting reliable communication across multiple floors. Item Type: Wireless Intercom Doorbells Material: ABS Usage: Homes, hotels, villas, factories, hospitals Outdoor Doorbell: - Battery: 2 x Built-in rechargeable lithium batteries (2000mAh each) - Operating Temperature: -20°C to 55°C - Wireless Range: Up to 1,000m (barrier-free); 20–50m (with barriers) - Wireless Frequency: 410–490 MHz - Battery Life: Over 8 months (under typical usage) - Waterproof Rating: IP54 - Dimensions: Approx. 121.5 x 61.5 x 31.3 mm (4.8 x 2.4 x 1.2 in) Indoor Doorbell: - Battery Life: Approximately 1 week (under typical usage) - Waterproof Rating: Not applicable - Dimensions: Approx. 125 x 70 x 56 mm (4.9 x 2.8 x 2.2 in) Package Includes: - 1 x Outdoor unit - 1 x Indoor unit - 1 x Charging base - 1 x DC charging cable for outdoor unit - 1 x USB-C charging cable for indoor unit - 1 x Screwdriver - 1 x User manual Notes: - Indoor and outdoor units include built-in batteries. - Avoid placing the product in highly corrosive, excessively humid, or high-temperature environments.