Fangrui Product Details A More Complete Brewing Airlock Kit - If You Need A Fermenting Airlocks That Can Be Used For A Long Time And You Dont Want To Buy Them Often, But You Also Want A Favorable Price. Then Get Airlock Combination. You Get 6pcs Bubble Airlocks + 6pcs #6 Stopper + 12pcs Grommets.just Drilled 3/8inch Hole For Grommets Or 1inch/1.28inch For Stopper On The Lid Improved High Transparency Bubble Airlock - Different Than Other Normal S Shape Airlocks In The Market,our Fermentation Airlock Made Of Healthy Material,more Harder (no Fragile)and More Transparent.(clearly See The Whole Fermentation Process)apply Pressure Slowing To The Airlock When Inserting Into The Drilled Plug/stopper And They Last A Long Time As It`s Transparent Wine Brewing Airlock. Improved Cap Off -this New Type Of Dust Cap Has A Zigzag Design On The And Not Slide When Opened. There Are 3 Buckles Inside, It Down Gently, You Can Close It With A Snap, Pull It Up And Rotate To Open It. The Lid Does Not Need To Be Drilled As There Is Space