But it is a stainless steel tumbler! :D
A product originated in South India, until someone corrects me. Not only are they adorable to behold (filter coffee?), but they magically keep water inside it all cool, and are considered to be the most essential asset in the war of holding down the corner of a leaflunch. Darn those flying leaflunches *shakes fist*.
It’s a part of my culture. But more importantly: it’s a hilarious pun.