This shirt has been designed to be worn under ballistic vests with a different fabric around the torso to help dissipate the heat generated by the vest and protect against skin irritation caused by friction with the vest.
The sleeves are made of nylon and cotton in a RIPSTOP weave (a tear-resistant fabric that protects the garment during use) in MP Camo. They are the only part that is camouflaged because they're not covered by the vest.
Elbow pads conform to the arms with an inner elastic band and can be exposed with sleeves rolled up "SEAL style" or removed. The design recalls Crye Precision's Gen.2.