Thermoses with a hinged lid

 

— a variation of the covers described above, which, when opened, is not completely removed, but leans to the side on a special mount. This reduces the likelihood of loss: in fact, you can only lose the lid along with the thermos itself; and a latch, spring, or the like is usually provided to hold the lid in the open position. On the other hand, the mount somewhat affects the price and dimensions of the vessel. This disadvantage is the least critical for flasks and mugs (see "Type"), and it is among these types that hinged lids are most often found.