This is the Geissele URG-I near clone upper. The specs are as follows
Milspec upper receiver
Geissele marked 14.5" Govt profile cold hammer forged chrome line barrel 1-7 twist.
Surefire 4 prong flash hider.
13.5" MK 16 Mlok rail
Mid length gas system, .76 port, Geissele low profile gas block
Geissele Charging Handle, Bolt Carrier Group, Braided Spring, and Buffer.
For those of you who care, this is not clone correct in that the upper receiver is a Colt, the barrel and gas block are DD, the BCG is various including FN and Colt. Effectively the military spec involved cannibalizing a lot of existing inventory.
The all Geissele version which you can buy on their website or various online retailers is not inexpensive, the suggested MAP pricing is $1,400.
Having said all of that, the upper is fantastic. We had two uppers on the range this weekend, one was outfitted with an Eotech plus magnifier and the other with a 1-8 ATACR. With 77 grain IMI ammo, both shot 5 shot groups of less then 1 moa (barely). We moved from the zeroing range to the variable target range (18 inch torso steel) from 100 yards to 1,000 yards with targets in 50 yard increments. The Eotech version tapped at around 450 yards with the 3x magnifier, just hard to get a site picture. The LPVO upper ran out hits to 700 yards. We were just resting the guns on a backpack shooting prone, no rear bags, no bipods, no levels, ect.
I know that on this forum people like building and have phenomenally accurate rifles. For those of you who want a soft shooting, very accurate, highly reliable rifle I would give this upper a look.