New SRAM 10A Torpedo fixed/freewheel internal gear hub. Black aluminum body, 32 hole, 120mm axle spacing (can increase with spacers).
New in box with all hardware included- 18 t cog, axle nuts, etc. NOS new old stock from 2008 or so.
Toggle between fixed gear and freewheel without removing wheel from bike. End of axle has a fitting for flathead screwdriver- twist and it internally shifts from fixed to FW and vice versa.