This barrel is threaded in the SIG Left Hand 13.5X1 threads. however, even if not threaded, a new barrel would not necessarily be needed as any competent gun smith could thread this barrel for you (in the much more common thread pattern 1/2 X 28.

Jason, yes, it is threaded 13.5×1 LH and hasan A2-Flash Hider. You could use a thread adapter to be able to use more common thread suppressors.

The MPX Pistol barrel is capped with an A2-style flash suppressor and is threaded for 13.5×1 LH suppressor use.