Please note, this item ships from an international seller. Expected delivery is 10-15 days. Specification: Material: Steel Diameter: 130mm (due To Manual Measurement, There Will Be An Error Of 1-3 Mm.) Combination: 11-13-15-18-21-24-28-32t Combination Name (group Name): 11-32t Compatible Chain: Ig/hg Speed: 8 Speed Feature: 1.durable 8-speed Atb Tape, All-steel Design. Suitable For Mountain Bikes. 2.the Sprocket Adopts A Computer-designed Tooth Structure And A Contoured Shift Gate, Which Can Achieve Smooth Shifting Even Under Load. 3.through Finer Beat Control, Tight Transmission Ratio Can Use Energy More Effectively. 4.the Nickel-plated Surface Has Wear Resistance And Corrosion Resistance. 5.corrosion-resistant Steel Cassette Lock Ring. Package Including: 1 X Bike Freewheel ?Multi-speed adjustment? - This bicycle flywheel is designed for 8-speed bicycles. It is suitable for chain links between 11 and 32 T. ?Hollow Design? - High pressure steel plate, nickel and chrome plating, with hollow design, weight reduction, super wear-resistant steel. ?High Quality? - This freewheel is made of high quality steel, which is high strength, rust-proof, non-deformable, wear-resistant and durable. ?Runs Smoothly? - The flywheel is equipped with high-precision threads that can be connected to the bicycle hub and run smoothly. ?Improved Design? - We specially designed our tooth profile and use a narrow tooth design to prevent the chain from falling on the reverse pedal.