USB Stick of Dahua that has a capacity of 8GB. Assuming that the average size for a photo, an MP3, and a Video is 2MB, 4MB, and 500MB respectively, then this USB can store approximately up to 4,000 photos, or 2,000 MP3s, or 15 Videos.
Its interface is USB 2.0. It is an older version, compatible with almost all devices but with slower data transfer speed (480Mbit/s) compared to newer versions.