This is the Sig 556. Sig Sauer was here in town.

SIG 556 ER features a 16” military grade cold hammer forged barrel, chambered in 5.56mm NATO, with a twist rate of 1 in 7”. The flash suppressor uses a standard .5 x 28 TPI thread pattern, ensuring compatibility with after-market accessories. The forearm housing the [...]

I like this Sig Knife. I picked it up at a Gun show in Fort Worth, TX.