Many security systems and dashcams use sequential alphanumeric naming (like AR 00101, AR 00102) for exported MP4 clips. Technical Specifications for "AR" MP4s
The "AR" prefix often refers to Advanced Recording Format (.arf) used by Cisco Webex. Since yours is an MP4 , it has likely already been converted from its original meeting format to be playable on standard devices. AR 00103b mp4
Must use even numbers for width and height (e.g., 1280x720). Constraints: High Profile, not exceeding Level 5.2. 1280x720). Constraints: High Profile
Based on technical standards for files with these identifiers, Likely Contexts AR 00103b mp4