SRAM XPLR PG-1231 Cassette - 12-Speed, 11-44t, Silver, D1Maximum range, minimum fuss. This SRAM XPLR PG 1231 12 speed 11 44t cassette provides 2x range in a 1x package and fits on a traditional 11 speed driver body for broad integration. The smooth cog progression keeps jumps between cogs tightest when it's time to go fast, with more meaningful gaps for climbing. 12 Speed cassette is designed for use with XPLR 1x rear derailleurs 400% range gives the coverage 1x riders want Compatible with SRAM 12 Speed