North Mountain Supply 6.5 Drilled Rubber Stopper - Pack of 6. High Quality Custom Blended Materials - Designed to be Slip Resistance and Create a Reliable Airtight Seal. Drilled to fit all standard size fermenting airlocks. Made in Italy! To promote a positive and satisfying customer experience, this product is covered by North Mountain Supply's 30 day hassle-free replacement program, in the event the product is damaged or defective.