On Friday, U.K. defense contractor BAE Systems announced that it has concluded a major arms sale to the Sultanate of Oman, involving 12 Typhoon fighter jets and eight Hawk training jets. At the request of its customer, BAE declined to specify the value of the contract, but news sources such as The Wall Street Journal posit a total deal value of $4.1 billion, with perhaps as much as $820 million being paid up front.

Oman has a long history of patronizing BAE for its military aircraft. Its air force currently trains on older BAE Hawk jets, and flies Jaguar fighter jets.

In a press release on the deal, BAE confirmed that it will provide after-sale in-service support for the jets to the Royal Air Force of Oman. BAE further advised that it expects to begin delivery of the jets to Oman in 2017.