From the residue of yesterday's hydration mix to last week's tap water deposits, your CamelBak Hydration Reservoir needs a helping hand in keeping it clean and free of weird tastes and funky build-up. The CamelBak Cleaning Brush Kit restores your hydration reservoir to virtually new condition, eliminating the build-up of gunk with its large reservoir brush and skinny tube cleaner. It's designed primarily for CamelBak Reservoirs, but it also works with many hydration reservoirs on the market.