Very rare complete set of (6) 1912 brass Thermos Cups with locking ring. All are sound and hold liquid. All lettering on bottoms clear and legible. Only notable condition issue is that one cup has small dent on bottom, but still independently stands correctly. I did not attempt to “bang-out” this dent, nor did I attempt to clean or polish any of these vintage items. Very rare set they is in very good condition. Please see pics for further description and condition.