Stainless Steel Hip Flask Two Sizes. The Stainless Steel Hip flasks are offered in 2 sizes: the larger Hip Flask holds approx 170ml , 6 oz including a funnel and presentation box. The Smaller Hip Flask holds approx 85ml , 3 oz and is presented in a gift box without funnel. Both Stainless Steel Hip Flasks have captive screw tops and both can be engraved with a name or logo so would make a great gift. Funnel available.