Product Description NAS (Nissin Air System) is Nissin's newly developed 2.4GHz radio transmission wireless flash system.Flashgun comes complete with Nissin Air 1 Commander, which can perform the following functions:-Controls the flashgun by a reliable 2.4 Ghz radio system up to 30 meters/100 feet away from Commander. Can control up to 21 flashguns at any time. (3 Groups A, B and C, 7 Flashguns per group) Controls TTl Exposure Compensation +/-2Ev. Transmission channels and radio transmission IDs can be set to prevent misfiring in the event of signal interference on the same channel. Controls manual power by 8 steps.Controls manual zoom from 24-200mmHigh Speed Sync, 1st and 2nd curtain sync options, Af assist light control. Simple easy dial selector. Box Contains Flashgun,stand,case,commander