The Sawyer Water Filter ! Both Ends ! 5/16 " ID Fits So Perfectly ! A Perfect Grip ! On Or Off ! Prying ? Optional ! Cut As Needed ! Inside The Bottle Or Out ! Food Grade Soft Silicone ! And The 1/2" OD ? Impressive ! Snow White ? Almost ! And So Soft And Rubbery ! Thanks Amazon ! All Good ! 10 Feet !