Profile Design 43 ASC Carbon Aerobar Extensions - Carbon 340mm BlackProfile Design 43 ASC Carbon Aerobar Extensions Carbon 340mm Black. The 43 ASC Aerobar Extensions are intended to optimize the aerodynamics of your existing bars but pairs exceptionally well with either the Race+ or Ergo+ armrest. Giving you the ideal supportive position which again will help you be relaxed while riding and the key to speed is relaxation. The fit by the wrist area is designed to smooth airflow over the arm and to increase contact area