Compared the previous Guidering M, e*thirteen shaved 11 grams off the new SL Guidering, while increasing fold-over strength and impact resistance. Features: Long-wearing shape and finish to ensure chain stays put even after months of use Direct mount guiderings are compatible with e*thirteen cranks that use the Quick Connect interface Machined from EXA+ Aluminum 5mm thickness SL Guiderings are machined with a -8mm offset and work with BOTH boost and non-boost chainlines, depending on spacer orientation of Gen 3 and 4 e*thirteen cranksets Compatible with 8, 9, 10, 11 and 12-speed drivetrains Specs: Drivetrain Speeds 12 Drivetrain Speeds 8 Material Aluminum Drivetrain Speeds 10 Drivetrain Speeds 9 Direct Mount Type Direct Mount e*Thirteen Tooth Count 28 Drivetrain Speeds 11 Ring Position/Type Single Defined Color Black Round or Oval Round