Answer your door no matter where you are from your smartphone with 1080p HD day and infrared night video and two-way audio. Experience long-lasting battery life, custom alerts, privacy settings, and more. Get alerts when motion is detected or someone presses Video Doorbell. Connect to existing doorbell wiring or pair with a Sync Module (sold separately) to engage live view and two-way audio on demand. Choose to save and share clips in the cloud with a free 30-day trial of the Blink Subscription Plan or locally with the Sync Module 2 and USB drive (each sold separately).Designed for every home, go wire-free or connect to existing doorbell wiring to also sound in-home chime. Set up yourself in minutes with the two included AA lithium batteries then connect to wifi in the app. Works with Alexa — receive alerts and answer with two-way audio. When wired or paired with a Sync Module, just ask Alexa to answer the front door. This package includes one Video Doorbell, 2 AA 1.5V Lithium Batteries, 4 Screws, 1 Case Opening Tool. Does not include Sync Module 2 which can be found in all “Systems” above (recommended for optimal use while on battery). Blink Video Doorbell Standalone does not include Sync Module 2. Without a Sync Module, live-view and two-way audio are available only in response to a doorbell press or motion event. With a Sync Module or Sync Module 2 get these features anytime on-demand.