This is the Gen 2 that has been “updated to accommodate the multi-caliber functionality of the platform.”

Gen 2 UPC:�
798681537662
Description:�
SIG MPX PDW PST 9MM 30R B FLD
Brand:�
Sig Sauer
Model:�
SIGMPX PDW W/ Aluminum KeyMod Hand Guard
Type:�
Pistol: Semi-Auto
Caliber:�
9MM
Finish:�
Black
Action:�
Semi-Automatic
Stock:�
Folding SBX (Stabilizing Brace)
Sight:�
No Sights
Barrel Length:�
8
�Overall Length:�
17
Weight:�
5 lbs
Capacity:�
30+1
# of Mags:�
1
Safety:�
Ambi Thumb Safety
Receiver:�
Aluminum
Packaging:�
Plastic Case
Features:�
Short Stroke Piston System, Handstop;
Ambidextrous Selector, Mag Release, Bolt Release

HI Victor, it is Gen 2.
Taking the market by storm, the Sig Sauer MPX Pistol has redefined the submachinegun category. Every component of the MPX has been thoroughly designed and rigorously tested to ensure reliability in any circumstance. Features AR-style ambidextrous controls, 8" barrel, rotating bolt system, short stroke piston, flared and beveled magwell, monolithic upper receiver, Keymod aluminum handguard with pistol stabilizing brace, and a 30RD 9mm magazine capacity. Comes with one 30RD (Gen 2) magazine.