What Our Gearhead(R) Experts Are Saying:"I wore this through a stretch of chilly fall mornings that never quite justified a full winter kit, and it hit the warmth level exactly right. The reflective panels also gave me some peace of mind riding out before the sun was fully up."Early fall and late spring live in a gray area, too cold for summer kit but not cold enough to justify a heavy layer, and Castelli built the Puro 4. 1 Long-Sleeve Jersey for exactly that window. We love how the 3D knit fabric traps more warmth than its weight suggests, so a ride that starts chilly never has us second-guessing the layer we chose. The close-to-body fit moves with every position without ever feeling restrictive, thanks to a high-stretch build that prioritizes range of motion over anything boxy. Reflective panels on the shoulder and heat transfers on the pocket add visibility for the early starts this jersey is made for, while three rear pockets and a gripper waist keep everything in place from first pedal stroke to last.