This is a Sram DUB Bottom Bracket Preload Adjuster Kit. It is a spare part for SRAM Dub bottom brackets and includes a screw, outer ring, and two inner rings (non-flanged and flanged). The flanged version is compatible with XX1 and X01 DUB cranks, excluding fat bike models. This kit is listed on pages 45 and 79 of SRAM's 2020 Spare Parts Catalogue.