A base layer can make or break a cycling kit. One that is not the right material or is poorly designed can cause a rider to be incredibly uncomfortable. For a base layer to be well-made, it must use a breathable material that will regulate a rider's temperature, and be designed to fit the part of the body that will carry it tightly. This base layer from Santini does all of this and more. It's sleek, comfortable, and for sure to be the perfect base to any cycling kit.