Mike, this is direct impingement. You can also just barely see the gas tube between the delta ring and the receiver in the picture.

Mike, Direct gas impingement with carbine length gas system. .075 gas block. Only piston action is locking lug bolt inside of bolt carrier tube.

Mike, the DPMS RFLR-G2AP4 GII AP4 20+1 308WIN is "Direct Impingement" operated Sir.

its a direct Impingement system see **** Specifications and Features:
DPMS GII AP4 AR Style Semi Auto Rifle RFLR-G2AP4 (60220)
*********Direct Gas Impingement Rifle System
.308 Winchester (Accepts 7.62x51 NATO)
16" Lightweight 4150 Steel Barrel (Chrome Lined)
1:10" Twist Rate
Forged 7075-T6 Aluminum Upper/Lower Receiver
Type III Hard Coat Anodized Teflon Coated Finish
A3 Flat Top Upper Receiver (Mil-STD-1913 Picatinny Rail)
DPMS Cancellation Muzzle Device
19 Round Magazine
DPMS LR-308/SR-25 Compatible Magazine Pattern
F Marked Front Sight Base
Magpul MBUS Rear Sight
Glacier Guard Polymer Hand Guard
A2 Polymer Pistol Grip
Standard AR Fire Control Group
M4 6 Position Collapsible Stock
Overall Length 34.25" Collapsed
Overall Weight 7.25lbs
Matte Black Finish