All-new Blink Video Doorbell + Outdoor 4 XR wireless security system delivers extended monitoring with up to two years of battery life per set of three included AA Energizer lithium batteries. The second-generation Video Doorbell and fourth-generation Outdoor 4 cameras provide head-to-toe HD viewing and 1080p live streams with infrared night vision. Paired with the included Sync Module XR hub, position up to two Outdoor 4 cameras up to 400 feet from your home for comprehensive perimeter coverage. Control and monitor your property remotely through the Blink app with two-way audio communication, ensuring security and peace of mind whether you're home or away.