Measures 2.5" square, 2.1" tall. It's one solid piece, the knob doesn't turn. No holes for mounting to anything. My best guess on the lettering (x's are illegible): Top: COLBOR x x Bottom: x x x x ERS MA x x ' Y. There's also an "H" stamped right in the middle of the knob. Found in a farm field in Chesapeake, VA adjacent to a railroad track.Posted this and now I see my pics won't attach. Grrr!!