A.T.&T. Co. aka AT&T Glass Insulator CD 121 Circa 1900

Been a bit since I posted an insulator. Usually it is because I forget which ones I already have. Bought this was because I thought it was green but it turned out to be the more usual blue/green. Still I got a good buy and you can still get 100 year old items for less than $10, possibly less than $5.
This one is marked XO or OX on the top which probably refers to the shop. People got paid on how many were made so a shop marking is on the top. Also it is possibly made by Brookfield for AT$T. Please note how old school the A.T.&T. Co. looks. Takes much longer to type though.
I think next time I will take a pure green insulator with me so I will know what real green looks like.