This is for use with a threaded mountain bike bottom bracket shell measuring at either 68 or 73mm. The threaded cups for this are black or red and you can choose from either of the top end bearing options of ZERO or XD15. This bottom bracket will only work with a 24 mm MTB crank spindle. The package includes a GXP spindle adapter sleeve, 3 bottom bracket spacers, 6 plastic spindle spacers, 1 wavy washer, and 2 radical decals.