Feature: 1. Easy To Use: Wireless long distance about 1000 meters, no network, no wiring, power on and use. 2. Intelligent Intercom Chip: The use of special intelligent intercom chip, strong penetration, suitable for floors 1 to 8 floors, the villa home preferred. 3. Material: The keys are made of plastic and silicone structure, the surface of the high gloss uv process, super feel. 4. Humanized Design: Intelligent humanized design, with intercom light and power light display, the user can see at a glance. 5. IP54 Waterproof: Wireless call outdoor doorbell with IP54 waterproof technology, can withstand harsh environments. Specification: Item Type: Voice Intercom Doorbell Product Material: ABS Battery: 3 x Li Polymer 2000mAh (Included) Working Temperature: -20℃-55℃ Wireless Distance: Approx.1000m / 1093.6yd (Without Obstacle), 20m-50m / 21.9-54.7yd (With Obstacle) Wireless Frequency: 410M-490M Working Time: Outdoor Doorbell > 6 Months; Indoor Doorbell About 1 Week Waterproof Level: Outdoor Doorbell IP54 Weight: Approx.447g / 15.8oz Outdoor Doorbell Size: Approx. 18 x 61.6 x 121mm / 0.7 x 2.4 x 4.8in Indoor Doorbell Size: Approx. 18 x 116 x 56 x 70mm / 0.7 x 4.6 x 2.2 x 2.8in. Package List: 2 x Indoor Unit1 x Outdoor Unit3 x Power Cord 1 x Screwdriver2 x Base1 x User Manual