Sturdy and Durable: Mason jar fermentation kit made of 304 stainless steel material, won’t rust, bend or bulge like tinplate material. Kit includes 4 BPA free water airlocks; 4 stainless steel(84.3mm) wide mouth lids and bands; 6 silicone grommets, and the kit comes with everything to make fermenting very easy to do with less work Good Sealing: The lids have a silicone seal underneath to make things airtight, and the grommet and seals prevent new air from entering and the user adds water in the airlock, allows the gas from fermentation to be vented via the airlock without allowing outside air to enter Easy to Use: The split design fermenting lids is easy to screw and assemble, which keep your ferment going strong without risk of mold or explosion Fit Wide Mouth Mason Jar: Fermentation Lids fit small 4oz wide mouth jars all the way to large 64oz wide mouth jars, can be used to making kimchi, sauerkraut, hot sauce and so on 100% Risk-free Purchase: We promise a 2-year free warranty for your easy fermenter wide mouth lid kit. If you are not satisfied, we offer a new replacement instead or full refund