I had 4 of these mugs for at least 20 years, and I used them alot!  The covers needed replacing and I thought, how convenient it would be to have 4 more :  )  They are perfect when making a large batch of soup or chili and portioning directly into these containers..Presto-lunch is ready for the week!  with minimal dishes to clean up :  )  Grab a mug on the way out the door..They do not stain or crack or chip..they are tough!  and the right size for portion control!  They do not leak !  LOVE THESE!!