Parts constructed from stainless steel, CNC aluminum, high quality teflon bushings, and rubber o-ringsNewest evolution of the tried and true PSS ZERO trigger systemRedesigned safety lever with enhanced throw leverRedesigned low-resistance Zero trigger allows for quick and crisp trigger pullsAdjustable trigger alignment block allows trigger to interface with nearly any VSR-10 styled rifleStock configuration with rubber damper and silent shaft reduce overall noise from piston mechanism while shootingFriction-resistant piston design and precision CNC machined sear for consistent power per shotSP120 or below recommended for use, configurable for spring rates up to SP190