Aeronautical Engineers Inc (AEI) has launched the AEI B737-900ERSF, an Extended Range Special Freighter capable of carrying 13 positions, including twelve 88″x125″ full-height containers and one additional unit, with a maximum main deck payload of 57,700 lbs. Certification is anticipated by early 2029. The conversion includes a hydraulically operated cargo door and a Class E cargo compartment. It features a reinforced floor for heavy freight, a 180-minute ETOPS option for operational flexibility, and retains an auxiliary fuel tank for extended missions.

Source: https://www.stattimes.com/air-cargo/aei-introduces-b737-900ersf-for-extended-range-cargo-operations-1356921