Available in both Call of Duty: Vanguard and Call of Duty: Warzone, the Timeless Pack is an in-app purchase for some guns and flair, with proceeds going to the Call of Duty Endowment which helps unemployed and underemployed veterans in the US and UK find high-quality jobs.
The Timeless Pack includes:
More info about the Call of Duty Endowment and the Timeless Pack can be found on the Call of Duty blog.