5159 Hydration Pack Cleaning Kit thoroughly cleans Chill-Its hydration packs and replacement bladders (not included). Kit comes with a delivery system cleaning brush, tube-cleaning brush and bite-valve cleaning brush to freshen up all small compartments. This cleaning kit guards against dirt buildup in the hydration pack and maintains safe drinking water by scrubbing every section of the pack or bladder. Tube-cleaning brush extends all the way to the end of the line to scrub the entirety of the tube. Bite-valve cleaning brush is small enough to get even the smallest grime. Once clean, lay out all supplies on drying rack to air-dry.