Pocket Sprocket - Bike Drivetrain Cleaning & Transportation Tool Designed for effortless cleaning and transportation of your bicycle drivetrain, the Pocket Sprocket is a eco-friendly, 3D-printed accessory made from recycled plastic. Compatible with 12 mm thru-axles, this portable tool simplifies chain maintenance by allowing you to easily slide it over the thru-axle, place your chain in the groove, and clean or lubricate your chain, chainrings, and derailleur with minimal effort. Application: Remove the rear wheel, insert the thru-axle into the non-drive side of the frame, and slide the Pocket Sprocket over it. Route your chain through the groove, then reattach the thru-axle on the drive side, just like reinstalling your wheel. This makes chain cleaning quick and safe, and helps you transport your bike conveniently.