Daniel Defense: SPR Mid Length Complete Upper Receiver Group???

[Cameron]

Can anyone tell me the details about the DD SPR Mid Length Complete Upper Receiver Group? (https://www.danieldefense.com/?page=shop/detail&product_id=94)

http://www.danieldefense.com/img/product/6160a8d38f0b5ff25fc355ce68187898.jpg

I am interested to know who makes the barrels and the type of chamber etc.

Here is the one I just got for my LMT Lower
http://i275.photobucket.com/albums/jj290/c2008pictures/G%20Stuff/DD%20LMT/DDLMT02-1.jpg

Thanks very much

Cameron

[variablebinary]

LW 50 Stainless Steel and have 1:7 twist rate.

Specifications
Barrel Characteristics: 16″ 1:7 Twist
Barrel Weight: 1.8 Lbs
Barrel Construction: LW 50 Stainless Steel
Chamber: 5.56 NATO or .223 Wylde
Complete Upper Weight: 4 lbs 3 ozs
Bolt Carrier Group: MP Tested Military Specification Bolt
Flash Hider: A2 Bird Cage Flash Hider