Israel Aerospace Industries (IAI) announced Wednesday it had begun production of a custom outer wing design for its F-35I Adir stealth fighters, a $2.5 billion deal that will see the contractor build hundreds of wing pairs for the Israel Defense Forces over the next 10 to 15 years.

Israel is one of the few nations permitted to modify Lockheed Martin's F-35 fighter, which it has dubbed the F-35I Adir ("Mighty One" in Hebrew).

The Adir fighter actually isn't in use yet by the IDF — that's what these wings will go towards. Israel currently has 14 F-35s, but they're boilerplate A-models, not the modified Adirs, and will have to be retrofitted later. After it receives its first complete batch of 19, the subsequent 35 planes delivered will become the Adirs, the blog National Interest noted. The IDF should receive all those planes by 2024.

The deal signed with IAI by Lockheed Martin will see the company build 811 pairs of F-35 outer wings by 2034. The product itself is a sort of shealth for the wing below, made of a state-of-the-art composite material called Automated Fiber Placement (AFP), a 3mm-thick thread material woven together to create a surface that won't appear on radar screens, the Jerusalem Post explained.

The F-35 is already built to be nearly invisible on radar.

"The construction of the new production line significantly upgrades IAI's technological capabilities, automation and robotics, and will enable the company to establish itself as a major player in the military and civilian aerostructures," IAI said in a statement Wednesday.

"The opening of the production line constitutes a significant milestone in the realization of the company's strategy for building advanced capabilities in the field of composite materials manufacturing technology. Thanks to this move, IAI will belong to a ‘limited club' of companies with these manufacturing capabilities," IAI vice-president Shlomi Karako, said, World Israel News reported.

Israel became the first country to use the F-35 in combat this past May, according to the Israeli Air Forces, which said at the time the stealth plane had been deployed on two missions.