Complete coverage for your home — With Battery Doorbell 2K+ and Outdoor 4, monitor your front door and property with reliable 2K and 1080p HD video.See faces and deliveries in 2K — From friendly faces to deliveries left on your welcome mat, see it all with Battery Doorbell 2K+'s head-to-toe 2K view.Ring within your home — Connect Battery Doorbell 2K+ to existing doorbell wiring to sound within your home. You'll also get alerts on your Blink app with each doorbell press.Long-lasting battery life — Easily, wirelessly install both products and get months and months of power with the included AA Energizer lithium batteries and a Blink Sync Module Core.Built for the elements — Both devices feature weather-resistant designs made for rain, dust, and severe weather. Outdoor 4 works in temperatures from -4°F to 113°F (-20°C to 45°C).See and speak from the Blink app — Interact with visitors using live view, night vision, and crisp two-way audio.Smart detection — As part of a Blink plan (sold separately), get alerts whenever a person or vehicle is detected and enjoy features like Blink Moments, which stitches together clips into a single video to save and share.Works with Alexa — Connect to an Alexa-enabled device to engage multi-camera live view, arm and disarm your system, and more using your voice.Includes one Blink Battery Doorbell 2K+, one Outdoor 4 camera, one Sync Module Core, five AA Energizer lithium batteries, mounting kits for each device, a wall plate, a doorbell removal tool, wire extenders, a USB-C cable (for Sync Module) and power cord (for Sync Module).