The lid of the Big Mouth Bubbler is notorious for popping off during fermentation, especially when the seal is wet. These Lid Clips solve that problem. Fits only the PLASTIC Big Mouth Bubbler. Does NOT fit the glass Big Mouth Bubbler. These Lid Clips are made from a semi-flexible material to ensure a long life after repeated usage and to provide a "spring like" effect for a superior and tight clamp on the side walls of the Big Mouth Bubbler. The curvature of the Lid Clips provides just the right amount of clamping strength while the extra wide bottom lip ensures that the Lid Clips don't pop off during usage. Included are three (3) Lid Clips that snap onto the edges of your Plastic Big Mouth Bubbler lid. Designed for easy installation. No tools or fasteners are required...just snap them on and let your precious brew ferment with peace of mind. Fits universal (non-threaded) lid of the 5 and 6.5 gallon PLASTIC Big Mouth Bubbler. For safety reasons, the Lid Clips are rated to withstand fermentation pressures only up to a certain threshold to prevent expansion/explosion of the fermenter. That being said, most primary and secondary fermentations fall below this threshold. Each and every clip is tested on an actual Big Mouth Bubbler before being shipped. This is a 3D printed item, and as such, each item is unique and may have small and minor surface imperfections that do not affect the functionality of the item. Made in New Orleans.