The TastePURE XL Water Filter has GAC (Granular Activated Carbon) filtration to provide you with safe drinking water from any potable source and KDF to help prevent bacteria growth when the filter is not in use. Durable in-line, exterior mount filter has a wide body which provides more filtration and a high flow. Product includes flexible hose protector to minimize kinking that could impede water flow. When first attaching the filter to your water source, allow the water to run free for a few minutes to flush the initial loose carbon out of the filter. When the water runs clear, the filter is ready for use.