Lazer cut body-form fabric sleeves sit at 3/4 just above the elbow, with a silicone injected gripper to reduce slippage. This makes the jersey super comfortable on your arms, without ever digging into your skin. Also makes your arms look a bit ripped, so there are some extra gains in there.
To the back of the jersey there are 3 x rear pockets, with a reflective zipper to the central pocket. The pockets have been made a bit deeper, so you can put your phone in as well as gels, bananas or homemade trail mix in a ziplock bag. Your call on that, but the thick embossed silicone gripper strip will keep the jersey in place, and will keep your garms looking sleek, so you can focus on your fuel.