Alpine Aerotech Ltd. is a Bell Platinum CSF. The Aeronautical Accessories Brand is proud to distribute Alpine Aerotech's quality products, which are endorsed by OEMs. AAL Exhaust Ducts are cost-effective replacements for the OEM exhaust ducts. They include a newly designed Exhaust Duct Retaining Ring that distributes the axial load of the bolts/washers more evenly when secured in position over the new formed flange, which helps eliminate cracking along the old fillet weld area of the OEM exhaust duct. . Alpine Aerotech Exhaust Ducts exceed OEM specifications for design and manufacturing. They come supplied complete with comprehensive installation instructions, maintenance manual supplement, all hardware required for field fitment, copies of TC and FAA Approvals and certification. All workmanship and materials are warrantied by Alpine Aerotech for 1 year or 1000 hours of service (whichever comes first) after date of purchase.