Bottom Bracket not included Triple chainring Bottom Bracket Interface Type: Square Taper JIS Plastic chainguard 3a-5d This is extremely good value crank from the Shimano Tourney Series, with its translation and durability Ideal for MTB and trekking use. It has three chain rings for 6/7/8 speed chains and a solid square socket (inner bearing sold separately). The spool is also compatible with chain: Yes. ; Package Content: TY501 crank with chain rings, without inner bearing Use: Mountain Bike Features: Steel chain rings Case Width Side to Side: 68/73 mm Chain Rings Number Chain Rings: 3 ; Gear Ratio: 48-38-28 teeth crank , axle Socket: Square ; Chain line: 47.5 mm Chain Guard ; Chain protection ring ; Chain guard compatible 1809838(693-694,373-377)10/8----2:rtn on 9/14/22---1:rtn on 10/21/22