Cleaning your drivetrain is a breeze with the Pocket Sprocket. The Pocket Sprocket comes in three parts. Click them together, and you can use the Pocket Sprocket right away. You can find the instructions on the inside of the packaging. Simply slide the Pocket Sprocket over your 12 mm thru-axle, put the chain in the groove and clean or lubricate your chain, chainrings and derailleur with ease. - For easy cleaning & maintenance of the drivetrain - Prevents the chain from scratching the frame during transport - For 12mm thru axles - 3D printed - Recycled plastic