I have been carrying a gi canteen cup for .....wow..60 years. I was given one by my next door neighbor. He was a paratrooper during ww2.

He highly recommended it as the most useful item he carried. I agree.

Although the canteen I carry now is plastic, the cup is still a heavy duty
GI stainless steel one. Wish I still had the original but there have been several improvements.
Nomad