5 PACK Universal Rubber Stopper - Size #10 (With Hole) for PET Carboys customlabel3 The level of permeability is

The level of permeability is wide ranging and highly dependent on what material the O-ring is made from

Also available in Stainless Steel

The Micro Matic Keg Beer 3” Column Beer Tap Tower Insulation is a genuine Micro Matic draft tower for professional draft systems

This double walled tubing offers superior protection against oxidation

these draft boxes have everything on the same side you'll be pouring from

5 PACK Universal Rubber Stopper - Size #10 (With Hole) for PET Carboys customlabel3 The level of permeability isUniversal stoppers have a longer taper to help produce a better fit and a snug seal, and a lip which prevents them from falling into your container. Available with a 3 8 inch hole for an airlock, or solid with no hole. #10 size is recommended for PET carboys.