Wolf Tooth´s ultra-lightweight hex and bottom bracket spanner has a 1 inch ( 25 mm ) hex on one end and an external BB cup slot on the other end (also often used for centrelock rotors).The 1 inch (25 mm) hex end has magnets that quickly engage with the steel hex insert tools (not included).The side of the tool has a chain line measuring ruler.Includes spanner only.Steel inserts are not included, but can be purchased separately.Compatible with 1´´ hex drive interface.Inserted magnets allow quick engagement and disengagement of steel inserts.Compatible with 16 notch 44mm bottom bracket tool (or Centerlock Rotor Lockring tool).Compatibility25mm hex drivetrain on one end and 16 notch 44mm bottom bracket tool (or Centerlock Rotor Lockring tool) on the other endSpecifications.Weight:105gMaterial Aluminium 7075-T6Max.tightening torque:40NmColour:RedMade in USA.