Castelli made this as an aero rain jacket for team sky. the high-stretch fabrics with a smooth face make this their most aero race option. But it’s good for so much more: it’s packable and fits in a jersey pocket, it’s fully waterproof and seam sealed to keep the rain out, and it features a long tail to protect you from wheel spray, while the external pockets are handy for stashing food. The sleeves have a three-layer fabric for comfort on the skin, while the inner textile layer is eliminated on the main body to save weight and keep the piece compact for packability. Oh, and keep in mind that it’s cut for a skin-tight fit on WorldTour riders.