within the first week one of the o rings was lost that keeps it from leaking. Not sure how I lost it, as I hand wash and did not find it anywhere. However, I contacted thermos and they sent a new lid right away, free of charge. I used the thermos anyway, while the lid was being shipped and it still kept my coffee hot for hours.Thermos is a company I will now always trust, especially due to the great customer service I was given