One of 2 designs from 1941 produced by Ostby & Barton of Rhode Island and used by dairies participating in the Superman Defense Club milk program. Ring top features various initials of milk company sponsor, in this case a letter “M.” Only the third "M" variety we've offered in over two decades. Below the initial is a diagonal lightning bolt and below that an eyeball surrounded by accent lines. The brass plate snaps off from the base and the underside of the snap-off piece holds a paper sticker picturing and reading “Superman.” The paper has minimal microscopic wear with couple of tiny dots of missing color but to the naked eye it displays essentially Mint and this is one of only four we've seen as nice in five decades. The top of the snap-off piece has glossy and near full original luster. The entire ring base also has NM luster. Overall an outstanding example that is NM displaying Mint.