This is a genuine Paccar K37-1029 fuel/water separator. The K37-1029 is for  X12 and X15 2017 and newer. 

Cross Reference:

• Fleetguard FS20172
• Paccar K37-1010
• Paccar K37-1011
• Paccar K371010
• Paccar K371011
• Paccar K371029