Blink Video Doorbell + Sync Module 2 | Two-year battery life, Two-way audio, HD video, motion and chime app alerts and Alexa enabled Answer your door anytime, anywhere from your smartphone with 1080p HD day and infrared night video and two-way audio. Experience up to two years of powerful battery life, custom alerts, privacy settings, and more. Choose to save and share clips in the cloud with a free 30-day trial of the Blink Subscription Plan or locally with the included Sync Module 2 and USB drive (sold separately). Designed for every home, go wire-free or connect to doorbell wiring to also sound your existing in-home chime. Without wiring, you can use your Blink Mini camera (sold separately) as an indoor plug-in chime. Set up yourself in minutes with the two included AA lithium batteries then connect to wifi in the app. Works with Alexa ? access live view, two-way talk, receive motion and chime alerts, arm and disarm your doorbell, and more. Includes one Video Doorbell, one Sync Module 2, and mounting kit (including corner mount, screws, and anchors).