Following Service Bulletin DOES NOT APPLY for my Oil Cooler as the serial number is NOT in the indicated range. Service Bulletin from Airflow 2006X X-Series Oil Coolers, manufactured in 2019 with serial numbers K19-16202-25 through 40 Oil Cooler Service Bulletin 0001 – REV A June 12, 2023 2006X X-Series Oil Coolers, manufactured in 2019 with serial numbers K19-16202-25 through 40. Potential oil leak from the vanes and/or core area of the oil cooler due to potential manufacturing defect. The service bulletin only applies to 2006X X-Series Oil Coolers serial numbers K19-16202-25 through 40. We are still collecting data, if your oil cooler is outside the affected range, we are interested in knowing about any failures. Inspect your 2006X oil cooler data plate and determine if your oil cooler falls within this serial number range. If it does, do not continue to fly your aircraft. Send Airflow Systems an email at airflowsystems2@gmail.com with your contact information and we will send you a replacement oil cooler and return shipping instructions for your oil cooler. DO NOT THROW AWAY YOUR OLD COOLER, WE REQUIRE THEM FOR EXCHANGE AND INSPECTION.