The Blink Video Doorbell + Outdoor 4 System includes 4 cameras with HD resolution, LED display technology, and a 1ms response time. This wireless Wi-Fi system is designed for outdoor use and is compatible with Amazon Alexa for smart home integration. Each camera has a battery power source with a voltage of 5V and operates on the IP/Network surveillance technology. With a storage capacity of 64GB and a contrast ratio of HD, this system offers two-way audio and an operating range of 100ft. The sleek black design, along with Amazon compatibility, makes it a convenient and secure choice for both outdoor and indoor locations.