I use these whenever doing a full cleaning. Each pliable waterproof disc separates into two sheets. The inside one has a cutout to place between spokes and disc. The outside one has connecting velcro-like matching connector to the inner. Just mold around front fork and the rear around the stays. Keeps the brake discs protected from cleaning products that will make the braking squeak. Just remove and a little cleanup under and hang the covers or dry overnight. I've probably used on 25 cleanings now and I would purchase again.