The X block is rarely used. No matter the series (1963 thru 2021), most notes stop well before they reach the X block. 

While there have been about 2,000 distinct blocks printed since the current design $1 FRN's were released in 1963, there have only been seven "X" blocks: 1988A BX, FX, GX, LX, 1995 BX, LX, and 2009 LX.

That means this note came from the only FX block produced to date. And given that the F District of Atlanta is the 6th District, this is the only FX 6-0 Super Radar ever printed. 

The note will be well-packed and shipped by USPS Priority Mail with tracking. Bid with confidence; this is my 25th year buying and selling on eBay; I have maintained a perfect rating.