Our gilet is made from the softest fabric that has just tiny bit of stretch, with side panels made from jersey fabric so the whole vest fits to your shape!  We've added two pockets on the back as well as one on the front (women's only) that's big enough for a phone or credit cards. A two way zipper for extra comfort. The gilet is also windproof and showerproof and very breathable.
 
Picture provided of previous year's gilet as example of the cut and the fabric. Stretchy, mesh sides and definitely windproof.
 
NOTE: When choosing size, I found these run a bit looser than the jersey. I take an L in the  jersey and an M in gilet.