Boeing and ALAFCO Aviation Lease and Finance Company (ALAFCO) finalized an order for 20 additional 737 MAX 8s at the 2017 Dubai Airshow, doubling the lessor’s order book for the MAX airplane.

Kuwait-based ALAFCO, a global provider of commercial aircraft leasing products, now has 40 737 MAXs on order. The deal, valued at $2.2 billion at current list prices, was announced as a commitment at the Paris Air Show.

“Our customers rely on fuel-efficiency, reliability and low operating costs to be successful and the 737 MAX aircraft will meet the needs of our customers, and support ALAFCO’s future growth,” said Adel A. Albanwan, deputy CEO of ALAFCO. “We have had success with the 737 family in the past and are confident the 737 MAX will continue to help grow our business.”

“We are pleased to grow our partnership with ALAFCO and support their fleet expansion,” said Kevin McAllister, Boeing Commercial Airplanes president and CEO. “The 737 MAX 8’s ability to fly further than the competition while using less fuel is one of many reasons why customers like ALAFCO have helped make the 737 MAX the fastest-selling airplane in Boeing history.”

The 737 MAX has surpassed 4,000 total orders to date.