ARRMA Hard Servo Saver Spring 12x20mm ARAC8903 is compatible with ARA106040T1, ARA106040T2, ARA106042T1, ARA106042T2, ARA106044T1, ARA106044T2, ARA106046, ARA106048, ARA109001, ARA109011, ARAD80BS, ARAD81LG, ARAD81LR, ARAD83LG, ARAD84NW, ARAD84SW, ARAD88RL, ARAD89BB, ARAD89LL