A:Answer You can add up to 15 cameras in an Arlo SmartHub as long as they are compatible and the Arlo Smart plan in your account supports the total number of cameras you will have. If you will add Arlo Pro 3 cameras, they will come with a free Arlo Smart trial. When the trial expires, you have the option to purchase an Arlo Smart subscription. Without an Arlo Smart subscription, you can still live stream, and receive motion and audio notifications. Please check this link to learn more about the Arlo Smart plans : https://kb.arlo.com/88. ^RM