These are the extra additions for the Battlefield soundpack project. Found here https://modworkshop.net/mod/31598
Separately, these are the Menu Track and the Firerate rebalance.

To install the rebalance, put it into mods
To install the menu track, put it into mod_overrides

If you somehow ended up here by means other than my soundpack page, i'd recommend visiting that for more details on what these are.