Boot Flask Celtic Pewter. We offer a selection of 3oz (85ml) English Pewter Boot Flasks in various designs. This Pewter Boot flask has two Celtic wire bands around the top and bottom of the flask. All our Pewter Boot Flasks are presented in a gift box including a silky draw-string bag. The Boot Flask with Celtic bands will fit comfortably in your welly or boot when out and about. Our Boot flasks are very popular, and are used in all kinds of sports. The Celtic boot flask can be engraved with a name or logo or any personal message.