A Complete Brewing Airlock Kit – This kit includes 6 bubble airlocks, 6 #6 stoppers, and 12 grommets for long-lasting use. Designed for easy setup, simply 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 plastic, this fermentation airlock is more rigid and less fragile than standard S-shaped models. Its high clarity allows you to clearly observe the fermentation process. Apply pressure slowly when inserting into the drilled stopper to ensure longevity. Improved Dust Cap Design – Features a textured zigzag surface for better grip and anti-slip performance. The cap includes three internal buckles for secure closure with a snap. To open, gently pull up and rotate. The design allows gas to escape without requiring additional drilling in the lid. Reusable & Versatile – These bubble airlock sets are sturdy and reusable for multiple brewing cycles. Ideal for fermenting beer, kombucha, peppers, watermelon, salsa, and other fermented beverages. Provides an oxygen-free environment for safe and effective fermentation. Color: As shown in photo Material: Plastic Package Contents: 6 x Twin Bubble Airlock Sets (each set includes airlock, stopper, and grommet) Note: Light reflection and differences in display screens may cause slight variations in color between the image and the actual item. Measurement may vary by +/- 1-3 cm.