A Complete Brewing Airlock Kit – This kit includes 6 bubble airlocks, 6 #6 stoppers, and 12 grommets for long-lasting use. Designed for durability and convenience, it provides a reliable solution for home fermentation needs. Drill a 3/8-inch hole for grommets or a 1-inch to 1.28-inch hole for stoppers on the lid. High-Transparency Bubble Airlock – Made from durable, food-safe materials, this improved S-shaped airlock offers greater hardness and clarity compared to standard models. Its high transparency allows clear visibility of the fermentation process. Apply gentle pressure when inserting into drilled stoppers to ensure a secure fit and extended lifespan. Improved Dust Cap Design – Features a textured zigzag surface for better grip and anti-slip performance. The cap includes three internal buckles that allow for easy opening and secure closing with a snap. Simply press down to close and lift and rotate to open. The design does not require additional drilling, as ventilation gaps allow gas to escape safely. Reusable and Versatile Application – These bubble airlock sets are sturdy and reusable, suitable for multiple brewing cycles. Ideal for fermenting beer, kombucha, peppers, watermelon, salsa, and other fermented beverages. Provides an effective, oxygen-free environment for fermentation. Color: As shown in photo Material: Plastic Package Contents: 6 sets x Twin Bubble Airlock Note: Light reflection and differences in display screens may cause slight variations between the color of the item in the image and the actual product. Measurement allowance is +/- 1-3 cm.