This is one Lot (Qty.2) New Santron DC-18GHz SMA Female 2-Hole Flange Panel Mount with Extended Dielectric. Part Number: STI 1206-21-PG. .
Here are the basic:
Insulator length: 0.126" (3.2mm)
Pin length: 0.051" (1.29mm)
Pin size: 0.012" (0.3mm)
2-Hole Flange size: 0.63" x 0.236" (16 x 6mm)
Distance between mounting holes: 0.481" (12.2mm)
Data Sheet Drawing:
http://www.rfbayinc.com/upload/files/data_sheet/parts/sti_1206-21-pg.pdf
This is the SMA Female connector used in RF Bay, Inc. product where high frequency is involved and also in many designer kit in my eBay store.