Atrius Development 3 Position SIG MCX/MPX X-Series Super Selector Safety - ADG-FRS-AMBI-X

Enhance the performance and versatility of your SIG Sauer MCX or MPX platform with the Atrius Development 3 Position X-Series Super Selector Safety. This ambidextrous forced reset selector delivers precise control through three distinct positions, allowing shooters to maintain reliable semi-automatic function while gaining the mechanical advantage of forced reset in the third position.

Key Features

• 3-Position Operation: Safe, Semi, and Super-Semi modes provide versatile firing options with a crisp 90-degree throw and positive detents for reliable engagement from either side.
• Ambidextrous Design: Original Atrius ambi switch with textured, chamfered levers ensures fast, confident thumb activation under stress.
• SIG-Specific Engineering: Purpose-built trip base and trip clutch system optimized for gas-piston platforms including MCX, MPX, Rattler, and MCX-Spear LT Upper AR Conversion Kit.
• Premium Construction: Machined from heat-treated 4140 steel with a corrosion-resistant black nitride finish for exceptional durability.
• Drop-In Installation: Seamless fit with no trigger modifications or cutting required.

Benefits for Shooters

Traditional safety selectors limit options on SIG gas-piston platforms. The X-Series integrates a mechanically leveraged trip system that forces trigger reset after each shot in Super-Semi mode, enhancing control and follow-up speed without replacing your entire trigger group. This design reduces wear on internal components compared to full forced-reset triggers while delivering consistent, repeatable performance.

Specifications

• Positions: Safe / Semi / Super-Semi
• Style: Atrius Ambi Selector Switch (original design)
• Material: Heat-treated 4140 steel
• Finish: Corrosion-resistant black nitride
• Throw: 90-degree indexing
• Installation: Drop-in ready, no modifications necessary
• Origin: Manufactured in the USA

Compatibility

Compatible with MCX, MCX-Spear LT, MCX-Rattler LT, MCX-Spear LT Upper AR Conversion Kit, MPX PCC, and MPX-K platforms across generations (safety latch may need removal on early models). Works with mil-spec single-stage triggers that do not feature a U-notch or relief cut. Not compatible with certain drop-in cassette-style triggers, Geissele MCX/MPX-specific triggers, or the SIG Two-Stage Match Duo AR trigger.

Why Choose This Product

Designed specifically for SIG gas-piston firearms rather than adapted from AR-15 components, this selector offers a purpose-built solution that maintains the integrity of your platform while expanding your firing options. The robust construction and ambidextrous ergonomics make it ideal for professional, competitive, or recreational use.

Upgrade your SIG MCX or MPX today with this innovative safety selector to experience enhanced control and reliability in every shooting scenario.