BCA Gen. 2 High Performance AEG Motor (16TPA) (Long Axle / Short Axle)BCA 16 TPA neodymium magnet balanced motor is a fantastic general purpose motor upgrade. These can be installed into most stock guns to instantly improve trigger response. These 16 TPA motors pair extremely well with SHS gear sets for budget friendly high speed builds. Gen. 2 improvements include vented cuts on the housing to improve airflow and efficiency.