This FerMonster Solid Lid with Hole (6 & 7 Gallon) can be used with either a 6 or 7 gallon FerMonster. It has a 1 3/4" hole diameter in the center of the lid. This product doesn't come with the O-ring. You can get one.
Specifications:
Compatible with 6 & 7 Gallon PET Plastic Carboys
Lid hole fits any #10 stopper
Does not come with o-ring, click for compatible o-ring
