The Tru Tension Grime Guard is a protective barrier for your disc brakes, wheels and rims while you clean your chain and sprocket.Easy no mess cleaning.Increase Chain Life.Protect discs from contamination.Less Dirt Build Up.Compatible with all Road/Off-Road/MX models.The Tru Tension Grime Guard is a protective barrier which is designed to protect your brake discs, wheels and rims whilst you clean and lubricate your chain and sprocket. Allowing you to make easy work of this usually messy job. The grime guard has a handy tray that will easily catch all the dirty oil, run-off and cleaner thus protecting your flooring, paving, carpet and will keep your grass from getting damaged. using this handy tool will remove the risk of contaminating your brake discs and any braking surfaces with the lubricating oils on your chain.