Barsmith Sparkling Non-Alcoholic Margarita is a ready-to-drink, alcohol-free canned beverage from Barsmith, a Texas-based brand. It delivers notes of bright citrus, salt and agave, and is infused with a functional blend of 50 mg L-theanine, magnesium and lemon balm. It comes in 8 fl oz cans with 35 calories per can and retails for around $12 for a 4-pack.