Klean Kanteen Sport Cap 3.0 Replacement Cap - 3 Pack New design has a 25% higher flow rate than the previous version Valve won't chirp or whistle while you sip Cap fits all narrow-mouth Klean Kanteen Classic bottle sizes Clip an accessory carabiner (sold separately) to the integrated loop to hang your bottle from a backpack strap Klean Kanteen Sport Cap 3.0 bottle cap is not 100% leakproof, so keep bottle upright when possible