CD 292.5 KNOWLES 6 / "PATENT JUNE 17, 1890" // BOSTON (tougher marking with no "prism") -- great blue -- thumbnail chip under the ear on back (see "1" in the photo), BB ding above the B in Boston, a couple lher kisses and a scratch or two -- overall very nice! $230 plus actual postage.

NOTE: I'm selling these insulators on behalf of the Jim Fielding estate -- PayPal (no fee friends and family) or checks are both accepted - I'll provide instructions. I'll also be handling all the packing and mailing.