The AREX Delta is a true double action striker-fired pistol. As opposed to some hammerless pistols with fully cocked strikers, the Delta's striker spring is only partially compressed as a cartridge is chambered. AREX has found their Striker Double Action system to be inherently safer than a single-action fully cocked striker.The Arex Delta X has the 4'' barrel of the Delta M and the longer grip of the Delta L.