These cassette spacers meet the needs of cyclists looking to optimize their bike's drivetrain performance. By improving gear alignment and reducing wear, they extend the lifespan of your bike's components. Their construction and compatibility with various setups make them a practical choice for both casual riders and cycling enthusiasts. Features -Color:Black -Material:Aluminium alloy -Size:3.50X3.50X1.00cm/1.38X1.38X0.39in -Thickness: 1mm, 1.5mm ,2mm ,1.85mm ,2.18mm ,2.35mm -Enhanced gear engagement cassette spacers: provides precise alignment for the cassette, ensuring optimal gear function and improved riding efficiency -Quick adjustment capability cassette spacers: features a micro adjustment design for effortless tuning of gear gaps, promoting smoother shifting -Universal fit cassette spacers: compatible with a wide array of mountain and road bikes, making it a practical choice for cyclists of all levels -Sturdy build cassette spacers: made from aluminum alloy, providing high performance and reduced need for frequent replacements -Reliable cycling support: tailored to meet the demands of daily commutes and outdoor adventures, ensuring a dependable riding experience Package list: 12 x Bicycle flywheel washer