Castelli's desire to have a premium cycling layer to match any condition is palpable, and the Beta RoS Jacket fills the space of protection in damp conditions but above freezing temperatures. Somewhat the rainy and foggy counterpart to the Transition 2 jacket, the Beta RoS supports rides ranging from 46-64 degrees F but receives the "rain or shine" designation thanks to its Polartec NeoShell and Nano Flex Light fabrics, which block wind and water throughout the ride.You'll find the Beta RoS ideal as more of an element barrier than an insulated jacket -- although Castelli claims a surprising amount of warmth during cool weather riding. The front and upper sleeves receive the Polartech NeoShell barrier to fend off rain and winds facing you, while the rear is woven in Nano Flex Light to handle the less forceful rear-wheel spray. The 4-way stretch allows the Beta RoS to feel like it's next-to-skin while supplying enough freedom of motion that you'll be able to find it the ideal early-season racing jacket. Three rear pockets hold the standard provisions, and the large reflective panel boosts your visibility in low-light riding conditions.