Ceramic base with two brass lugs, original tag. Molded on top: "Aerial / Fleron Radio / Sentinel / Lightning Arrester / Ground"; on back: "Underwriters / Approval E-7191 / Nu-Blac / 17". M. M. Fleron ...
Marked on box: Electrad / Radio / Lightning / Arrestor / 428-430 Broadway / New York, N.Y.", on unit: "Type 100 / Pat. Pending." Porcelain type unit with two binding posts, one for antenna connection ...