Who cares if they're acceptable? They're NECESSARY. I, of course, own two metal flasks and have a couple cheap-o plastic flasks that we used in the past to smuggle bourbon into Braves games. Fuck $7 for a 16 oz. beer when I can get a coke for $4 or $5, drink some of it down and then pour in mah liquor. Now that's how you attend a sporting event, chaps.