The Red 4" Food Grade BUNA Gasket was specifically designed for our 4" Threaded Lids.

This gasket will cover more surface area than its predecessor, the Red O-Ring. Specially designed for Minibrew® so it will not fall out as you put it in place to screw into the threads of the fermenter.  

The 4" BUNA Gasket is standard equipment on all fermenter orders utilizing the 4" Threaded Lid.  

If your model utilizes the Red O-Ring, you can use either the O-Ring or the 4" BUNA Gasket.