BOSORIO 4 Pack Gaskets Compatible with ThermoFlask 16oz 24oz 32oz 40oz Water Bottle with Straw Lid, Replacement O Ring Rubber Seals Part（Not for Spout Lid and Chug Lid）

Perfect fit easy to install good quality

Bought these to replace what my kids had inevitably lost lol they work perfectly!

Fits the Costco Thermoflask well, doesn’t leak, and cost doesn’t break the bank. Would order again

Se me había perdido el empaque de mi termoflask de 40 oz y quedó perfecto

Bought the 16oz thermoflask, was on sale at costco. Didn't get around to using them until after the warranty was up but the rubber ring that goes around the lid kept coming off and was really hard to put back in. Just tried these to see if it would work, otherwise would have thrown away the bottles. They fixed the leaking problem and stay in place. ThermoFlask support told me to order from their website but these are definitely much, much cheaper

Changed out the seals on the lids of our Thermoflask 16 oz water bottles and they were a perfect fit.

I bought these after I purchased replacement from thermoflask, and they were so much better. I have a stash of thermoflask bottles for our family, and I recently purchased a bunch of replacement o-rings for them directly from the company. After washing them, they were all warped, and realized they were not the same as the original ones. So I decided to try these and they are an exact replacement. They go into the cap so easily and we have had no leaking issues. I’m definitely buying more!

These fit perfectly! Great purchase.