I bought this last night from a local big box store because the travel mugs I had been using have been severely distorting the taste of my coffee -- I thought stainless steel wasn't supposed to do that but it did.  I found this Keurig brand cup which has a black plastic internal liner.  It is the PERFECT size for the car, for the Keurig coffee maker and for the large cup size I like.  It also did not leak a single drop. Unfortunately, it still changed the flavour of the coffee quite a bit compared to a ceramic mug AND the coffee was luke warm within 30 minutes.  This was very disappointing for such an expensive containers.  It's going back.