Katadyn Steripen FitsAll Filter

Its unique design, featuring the filter cup and funnel fit, offers flexibility to filter water into water bottles with a wide range of mouth sizes, including narrow-mouth bottles such as commercial water bottles, soft drink bottles, canteens, and SIGG bottles. Compatible with wider-mouth bottles such as Klean Kanteen, Gatorade and Nalgene bottles. Only the cup is necessary.