CD 110.5 [050] National. This is the [050] embossing on the base with the pointed dot present at the top of the pinhole and a 1 embossed on the top. The exact embossing on the base is +NAT.INSULATOR CO.+ PAT. MAY. 1.DEC 25. 1883. JAN.1. OCT.7. 1884. This one has the complete threading but it has the segmented lines within the threading. Condition is about near tops for this with lots of dome glass. I have pictured it with a very small flea bite on the spiral just above the wire groove. You can rotate these any way you want but this peck is hard to spot regardless, There is also a small scuff on the very top. The non segmented thread version with the number 1 on the top is far less frequently encountered as compared the the segmented thread one. I am pricing this at a very fair $95.00 plus shipping. I can probably still get this delivered in time for Christmas. Search past listings and I don't think you will find one this nice at this price. First email.