Rate mark handstamp, FREE
A mark on a piece of mail by this wooden handstamp indicated that the mail had entered the mailstream free-of-postage. The marking head is a tight-grain hardwood such as boxwood. Two incised lines encircling the handle bulb are generally associated with products sold by E. S. Zevely, who owned a manufacturing shop in Pleasant Grove, Maryland. This handstamp was likely produced between 1850 and 1854.
Postal History Journal. May 1957, No. 1. pp 45-54.