Santini: Lined Windproof Gravel Cycling Jacket The Alpha Trail jacket is a revolutionary Santini product, the result of a combination of fabrics that makes it perfect when on your bike, but also during trekking or other outdoor experiences. The outer layer in ultralight shuttle fabric is enriched on the inside with the latest version of the Polartec® Alpha® Direct fabric with Merino wool. This patented active insulation is made possible thanks to Alpha's lofted fibers attached to a solid mesh core while the wool helps with thermoregulation. Polartec® Alpha® Direct is inherently hydrophobic, resists all moisture and dries incredibly fast. A small heat-taped zip pocket on the chest allows you to carry your personal items, while the mesh back pockets, reflective details and the ergonomic fit complete the garment and provide exceptional comfort.