20mm Vial Rubber Stoppers (100 count) Mushroom Self Healing Injection Ports Solid Seal, For Glass Vial and Liquid Culture Jars, Can Be Sterilized by Steam and Repeated Used(20mm)

Excellent. Exactly as described. Fits a 15/32 inch hole perfectly. Use a step drill bit for a super easy clean hole in a jar lid. Oreilly sells a kit that includes a step drill bit with the correct size. Best value for money. Excellent durability, I tested one by puncturing it 20 times. As long as you use slightly different spots it lasts easily 10-15 punctures with a 16 gage needle.

100% success with zero contaminates. No problems being pressure cooked at 15psi for 90 minutes. The ports can be used multiple times, but they're so cheap I use new ones each time. 100 for $10 is an excellent buy.

was very happy with the quality of the product

Fast shipping product as described and great price. Can’t really complain but made of a harder rubber than the higher quality product vacutainer type. Would buy again in a pinch

They work great. Be careful when using a hot tool to pierce it. The heat makes the self healing ability non existent.

These are game changers for liquid cultures for mushroom cultivation. Super cheap for how easy they make sterile spore and LC transfers.

Seals good works great. Use a punch as opposed to a drill bit. It will make the hole cleaner.

15/32 bit running drill in reverse for a clean puncture. Run reverse from topside. It will be a friction hole. Light cleanup on backside but stopper will seal perfect. Love the fit and seal