High Altitude Regulator ConversionFor units before build date 0719 on the serial # contains 4 jets#3.9= 6K to 7K#4.0= 5K to 6K#4.1= 3K to 5K#4.2= 2K to 3K
HAK Regulator Kit wGen9500DF, wGen9500DFc, and R12000DF units.Kit contains 4 jets***072019 build date and newer***#4.6= 6K to 7K#4.7= 5K to 6K#4.8= 3K to 5K#4.9= 2K to 3K