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.