I'm looking for a 16 ounce clear flask with a curved side so it will fit in the back pocket.

The GI flask is the right size but it lacks features I think are important.

First, the tiny cap and screws are inadequate for sealing the bottle from leaking. They are not fitted correctly and have no O ring.

Secondly, There is no loop for retaining the cap. Therefore I will loose it the first chance I get.

Does anyone know of a better product that will fit my parameters?