Atrius Development Ambidextrous X-Series Forced Reset Selector Features The X-Series Forced Reset Selector introduces a new trip system with a trip base and trip clutch allowing this selector to achieve universal fitment across a variety of Sig Sauer gas piston platforms rather than being limited to a single fire control group design. The 3-position configuration provides Safe Semi and Super-Semi positions giving shooters the same mechanically leveraged reliability found across the Atrius FRS lineup while extending compatibility to piston-driven systems. For gas piston platform shooters who need dependable repeatable control this trip system delivers consistent function across MCX MPX and Rattler platforms. The selector is machined from heat-treated 4140 steel and finished in a corrosion-resistant black nitride coating delivering hardcore durability that withstands rain mud sweat and sustained use without wear or degradation. The included FRS lever is dimensioned specifically for compatibility with MCX and MPX product lines while the original Atrius ambidextrous switch design provides aggressive texturing and chamfered edges for immediate thumb purchase under stress. For shooters who need fast confident manipulation on piston platforms this ambidextrous switch and durable construction offer speed without hesitation. Atrius Development engineered the X-Series as a drop-in performance upgrade for Sig Sauer gas piston platform owners swapping out the factory safety in minutes with no cutting or modification required. This universal design extends the proven Atrius FRS mechanical advantage beyond standard AR-15 mil-spec fire control groups to the growing lineup of Sig Sauer platforms. For sale at GrabAGun this selector suits Sig Sauer MCX MPX and Rattler owners looking for a robust USA-made ambidextrous forced reset selector built specifically for gas piston systems. Atrius Development Ambidextrous X-Series Forced Reset Selector Specifications Manufacturer: Atrius Development Model: Ambidextrous X-Series Forced Reset Selector Type: Forced Reset Selector Positions: 3 Safe Semi Super-Semi Material: Heat-Treated 4140 Steel Finish: Corrosion-Resistant Black Nitride Style: Ambidextrous Compatible With: Sig Sauer MCX MPX Rattler MCX-Spear LT Upper AR Conversion Kit Installation: Drop-In Origin: Made in USA Available At: GrabAGun