The term "add-on camera" for the Arlo Ultra 2 Spotlight camera means that this camera can be used as a complementary unit to an existing Arlo surveillance system. It is not designed as a stand-alone system, but rather as an extension for an existing system that contains an Arlo SmartHub or a base station.

This add-on camera can be connected and managed with the existing system to monitor additional areas of your home or property.