This rubber-arm anchor tee, complete with a spike in its base, is marked "Avon Swivel Tee 628374". The number "628374" is a British patent number that dates to the end of 1913, which makes this one of the earliest anchor tees. The "swivel" name was given because the tee would swivel around to some degree, as opposed flying off in the distance, after the golfer struck a ball placed thereon.