This is the specific product ID. Every video uploaded by an independent creator on the FC2 marketplace is assigned a unique number for cataloging.
If you enjoy a particular title, the safest and most respectful way to support the creator is to (or any authorized platform) and pay the required fee.
The following article explores the technical nature of these file types, the legal landscape of the FC2 platform, and the safety considerations for users interacting with such archives.
: Many sites hosting these filenames use aggressive pop-under ads and fake "Download" buttons designed to steal browser data. Direct Access