M4 Water Tight Lid with Internal Lock Ring and Super Thick Neoprene or EVA Seal (Fits all M4's)

New and improved lid for 2023 with internal lock ring to keep the super wide/thick neoprene foam gasket Or EVA foam gasket in place. Double acting seal is essentially leak proof. Includes a hyper flexible rubber lid vent to mitigate against tank vacuum during use, preventing  tank "puckering".  THE XXL LID SEAL IS .75 INCHES WIDE AND 4MM DEEP. Includes one foam lid seal/gasket.