One of the most storied platforms has been rewritten. Combining the AR, AK, and Swiss 550, the Sig Sauer 556xi is the most adaptive tactical carbine yet. In-field adjustment of almost every component is possible due to the serialized upper. The adaptive 556xi accepts multiple calibers and magazine types while featuring ambidextrous controls and a three-position adjustable gas piston operating system. The barrel, lowers, stocks, accessories, and handguards can all be adjusted to fit each specific mission.