It's slightly misleading to call the Assos NS. skinFoilsummers7 a body insulator, because it's designed to help you stay cool on super hot days, but we know what Assos is trying to say. SkinFoil Body Insulator is the catchall name for Assos' collection of baselayers, which range from ultralight layers to actual thermal garments, and the NS. summers7 just happens to fall on the warm weather end of the spectrum. Effective moisture management is key to staying cool, and the summers7's blend of nylon and polyester is specially engineered to transport sweat and vapor quickly away from your skin for effective evaporation and cooling. The form fit supports your muscles and prevents discomfort, and the sleeveless design reduces weight and helps prevent overheating when worn under a jersey or jacket.