ITEM NAME:Bike Chain Keeper Holder Dummy Sleeping Hub for Bicycle Clean Transporting Descriptio n Description: Uses: It is used to keep the chain tension when cleaning the chain or during bicycle transportation, to avoid the chain and the body rubbing against each other and causing scratches. Installation method: similar to the rear wheel, adjust the rear dial to the smaller fly so that the guide wheel and the roller are on a horizontal line, and the lock can be properly locked. Specifications: Material: Plastic + steel screws Colour: Black Size: see size chart Package Included: Bicycle Virtual Flywheel*1 Note: 1.Due to the manual measurement and different measurement methods, the actual size could be slightly different. 2.Please be reminded that due to lighting effects and monitor's brightness/contrast settings etc, the color tone of the website's photo and the actual item could be slightly different. We offer you what you need! Bike Chain Keeper Holder Dummy Sleeping Hub for Bicycle Clean Transporting.Uses: It is used to keep the chain tension when cleaning the chain or during bicycle transportation, to avoid the chain and the body rubbing against each other and causing scratches. Bicycle Virtual Flywheel 1.