First and foremost, the Racing Mid Layer jacket performs its intended task very well. In conditions where you've got your foul-weather jacket buttoned up against the elements, the Racing Mid Layer keeps your core warm without restricting movement. The jacket has a roomy fit through the shoulders, articulated arms, and a slim profile. The WarmCore insulation distributed throughout the body and arms is not bulky. A snug collar and the absence of extraneous pockets and zippers let the jacket slide freely beneath your outer layer. In general, the jacket's no-frills design helps it integrate easily with the other layers you're wearing. For instance, the simple, low-rise collar won't interfere with the various flaps and zippers that make up the collar of your foul-weather jacket.