The Aperta Battery Powered WiFi Doorbell Comes With A Battery Powered Chime Which Can Be Placed Almost Anywhere In Your Home. The Door Bell Has Been Designed For Domestic And Light Commercial Markets. The Doorbell Has A Record Facility Which Allows You To View And Talk To Visitors At Your Home Whether You're Home Or Not. The Free ESP Smartphone App Allows You To Receive Alerts To Visitors So You Can See Who Is At The Door And Engage In Two Way Communication. The WiFi Doorbell Is Supplied With An Installation Kit Containing Everything Required For Quick And Simple Installation. Requiring Wi-Fi Or 4G, It Is Recommended That The Door Station Is Programmed Prior To Installation. For A Successful Set Up, The Installer Must Ensure That The User's Smartphone Is Connected To The Wi-Fi Network, The Door Station Is Within The Network's Wi-Fi Range And That The Key/password Is Available.