Self Healing Rubber Injection Ports (48 peices) 13mm Rubber Bottle Stoppers (Steam Sterilization safe) for Sealing 1/4 inch or 7mm opening

48 - Rubber Bottle Stoppers Self Healing Injection Ports for Mason Jar Lids ... Use 1/4 inch drill or punch for tight seal. Use in your pressure cooker or autoclave. Fits 13 mm Bottles with 7mm or 1/4 inch opening. We use for liquid culture and BRF jars, test tubes and bottles. Its smaller size makes it more sanitary and easy to use and easier than drilling those big holes for the larger stoppers