Castelli's Ultraleggera Full Zip Short Sleeve Jersey is their lightest jersey. Made from their SGO.6 polypropylene mesh, it's cut to hug your torso and to eliminate any excess fabric flapping about when you battle into the wind. The polypropylene fibers in the fabric are hollow. This is the reason for the extreme lightness of the Ultraleggera Jersey. One of the fiber's advantageous properties is that it doesn't absorb water. After all, what good would a lightweight jersey be if it soaked up water like a sponge, got heavy, and stretched out of shape over the course of a summer afternoon ride? So it's light whether wet or dry, and the fabric is knit as a mesh. This all but guarantees its coolness when you're moving and can get some wind blowing over your body. A full length front zipper complements the mesh construction. In the heat of summer, there's nothing we like more for massive (and often necessary) ventilation.

The Castelli Ultraleggera Full Zip Short Sleeve Jersey comes in five sizes from Small to XX-Large and in three colors -- Black/white, Red/white, and White/red. It has three traditional rear patch pockets on the back, with the Castelli Scorpion logo in the center.