This thicker Lid O-Ring is suited to FermZilla Conical and All Rounder Models. All future models produced after 25/12/2019 will have these O-Rings as standard.
If you are experiencing leaking from the top lid section, this slightly thicker O-Ring will aid in resolving said leaking. To perform a leak test please remember to have the unit free of any liquid as that will absorb CO2.
If you are able to show us with a short video or photos that your unit is leaking from the lid. We will replace said O-Ring for free under warranty via mail.
It is also important to remember not to overtighten the stainless steel handles that may have come with your FermZilla. Over tightening will cause the opening to warp and not seal. The Handles should be able to freely rotate around the neck with little resistance.