Lids crack, lids break, sometimes they get really gross and you just want a new one.  Straw Friendly and Spill Proof: our  lid replacement is designed for all our tumblers, yes, it will fit ALL INERTmug product. Spill proof and splash resistant, you can cover it at the top of tumblers to prevent leakage; The center hole is straw friendly, will not affect your use