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"Innovative firearm accessories engineered for performance"

SI designs rugged, user-focused firearm components and optics. They make accessories like slide plates, charging handles, barrel clamps, red dots, and shotgun parts.

5.0★★★★★(82 verified SI reviews)
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7,545
Products
2,384
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Founded
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All SI Products (2,384)

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with Romeo-X Optic, 17+1 Capacity Buy Sig SAUER P365X-Macro 9mm 3.7" 2x17rd Pistol With Romeo-X 365XCA-9-BXR3-RXX online Sig SAUER P365X-Macro 9mm 3.7" 2x17rd Pistol With Romeo-X 365XCA-9-BXR3-RXX Buy Sig SAUER P365X Pistol 9mm Romeo-X XSeries (2) 12rd (365X-9-BXR3-RXX) online Sig SAUER P365X Pistol 9mm Romeo-X XSeries (2) 12rd (365X-9-BXR3-RXX) Buy Sig Sauer SURG556 5.56mm Rifle Suppressor Flat Dark Earth Cerakote online Sig Sauer SURG556 5.56mm Rifle Suppressor Flat Dark Earth Cerakote Buy Sig SAUER P226 X-Series Legion Carry Size 9mm 3.8in 3x10rd SAO Pistol online Sig SAUER P226 X-Series Legion Carry Size 9mm 3.8in 3x10rd SAO Pistol Buy Sig Sauer P226-XCarry Legion SAO Handgun 9mm Luger 10rd Magazines(3) 3.8 Barrel Optic Ready Legion Grey Cerakote online Sig Sauer P226-XCarry Legion SAO Handgun 9mm Luger 10rd Magazines(3) 3.8 Barrel Optic Ready Legion Grey Cerakote Buy Sig SAUER P226 X-Series Legion 9mm 4.4in 3x10rd Legion Gray SAO Pistol online Sig SAUER P226 X-Series Legion 9mm 4.4in 3x10rd Legion Gray SAO Pistol Buy Sig Sauer P226 XCarry Legion Handgun 9mm Luger 10rd Magazines(3) 3.8 Barrel DA/SA Optic Ready Legion Grey Cerakote online Sig Sauer P226 XCarry Legion Handgun 9mm Luger 10rd Magazines(3) 3.8 Barrel DA/SA Optic Ready Legion Grey Cerakote Buy Sig Sauer 8901534 P320 Slide Assembly with Romeo-X Pro & Compensator online Sig Sauer 8901534 P320 Slide Assembly with Romeo-X Pro & Compensator Buy Sig Sauer BuckMaster 3-9x50 Rifle Scope with BDC Reticle and 50mm Lens online Sig Sauer BuckMaster 3-9x50 Rifle Scope with BDC Reticle and 50mm Lens Buy Sig Sauer P320 Xten CarryComp 10mm 3.8in Black 15rd Striker Fired online Sig Sauer P320 Xten CarryComp 10mm 3.8in Black 15rd Striker Fired Buy Sig SAUER Romeo M17 Coyote Tan Reflex Sight 2/32 Moa Circle Dot NVG-Compatible online Sig SAUER Romeo M17 Coyote Tan Reflex Sight 2/32 Moa Circle Dot NVG-Compatible Buy SIG 1911 XCarry 45ACP 4.25" Barrel XRAY-3 Sights, G10 Coyote Grips, 8RD Magazines online SIG 1911 XCarry 45ACP 4.25" Barrel XRAY-3 Sights, G10 Coyote Grips, 8RD Magazines Buy Sig Sauer 1911 XCARRY .45 ACP 4.25" Barrel XRAY3 Sights 8RD G10 Grip Black online Sig Sauer 1911 XCARRY .45 ACP 4.25" Barrel XRAY3 Sights 8RD G10 Grip Black Buy Sig Sauer SOTD65114 Tango-DMR 5-30x56mm 34mm Tube Illuminated Reticle online Sig Sauer SOTD65114 Tango-DMR 5-30x56mm 34mm Tube Illuminated Reticle Buy Sig Sauer SOTD65113 Tango-DMR 5-30x56mm 34mm Tube MOA Reticle Black online Sig Sauer SOTD65113 Tango-DMR 5-30x56mm 34mm Tube MOA Reticle Black Buy Sig Sauer SOTD63114 Tango-DMR 3-18x44 34mm MRAD DEV-L 2.0 Black online Sig Sauer SOTD63114 Tango-DMR 3-18x44 34mm MRAD DEV-L 2.0 Black Buy Sig Sauer SOTD63113 Tango-DMR 3-18x44 34mm Tube MOA Reticle Black online Sig Sauer SOTD63113 Tango-DMR 3-18x44 34mm Tube MOA Reticle Black Buy Sig Sauer SORX1000 Romeo-X Reflex Sight 1x24mm Circle Dot Black online Sig Sauer SORX1000 Romeo-X Reflex Sight 1x24mm Circle Dot Black Buy Sig Sauer WRMPX-4B-9-SBR-35 MPX SBR 9mm 4.5 In 35+1 Black Folding Stock online Sig Sauer WRMPX-4B-9-SBR-35 MPX SBR 9mm 4.5 In 35+1 Black Folding Stock Buy Sig Sauer P320-XTEN 10mm Auto Recoil Spring Assembly 8901519 online Sig Sauer P320-XTEN 10mm Auto Recoil Spring Assembly 8901519 Buy Sig Sauer Whiskey 4 SOW43004 3-12x44mm 30mm SFP Matte Black Scope online Sig Sauer Whiskey 4 SOW43004 3-12x44mm 30mm SFP Matte Black Scope Buy Sig SAUER Whiskey 4 3-12x44mm Rifle Scope 30mm Tube SFP Quadplex Reticle online Sig SAUER Whiskey 4 3-12x44mm Rifle Scope 30mm Tube SFP Quadplex Reticle Buy Sig SAUER Romeo-X Compact Red Dot Sight 24mm Circle Dot Reticle Black online Sig SAUER Romeo-X Compact Red Dot Sight 24mm Circle Dot Reticle Black Buy Sig Sauer E9MMB1ROSE50 Rose 9mm 115gr FMJ Ammo 50 Rounds online Sig Sauer E9MMB1ROSE50 Rose 9mm 115gr FMJ Ammo 50 Rounds Buy Sig Sauer E9MMA1ROSE20 Rose 9mm 115gr JHP Ammo 20 Rounds online Sig Sauer E9MMA1ROSE20 Rose 9mm 115gr JHP Ammo 20 Rounds Buy Sig Sauer P365 AXG Legion 9mm Compact Pistol: XRAY3 Sights, 3x17-Round Mags online Sig Sauer P365 AXG Legion 9mm Compact Pistol: XRAY3 Sights, 3x17-Round Mags Buy Sig Sauer 9389TXR3AMBI P938 9mm 3" Rosewood Grip Two-Tone Micro-Compact online Sig Sauer 9389TXR3AMBI P938 9mm 3" Rosewood Grip Two-Tone Micro-Compact Buy Sig SAUER P320 Carry 9mm/40/.357 Black Medium Grip Module (8901514) online Sig SAUER P320 Carry 9mm/40/.357 Black Medium Grip Module (8901514) Buy Sig Sauer P226 XCarry Legion Handgun 9mm Luger 18rd Magazines(3) 3.8 Barrel SAO Optic Ready Legion Grey Cerakote online Sig Sauer P226 XCarry Legion Handgun 9mm Luger 18rd Magazines(3) 3.8 Barrel SAO Optic Ready Legion Grey Cerakote Buy Sig Sauer P226 XCarry Legion Handgun 9mm Luger 18rd Magazines(3) 3.8 Barrel DA/SA Optic Ready Grey Cerakote online Sig Sauer P226 XCarry Legion Handgun 9mm Luger 18rd Magazines(3) 3.8 Barrel DA/SA Optic Ready Grey Cerakote Buy Sig Sauer P226-X Legion SAO Handgun 9mm Luger 18rd Magazines(3) 4.4 Barrel Optic Ready Legion Grey Cerakote online Sig Sauer P226-X Legion SAO Handgun 9mm Luger 18rd Magazines(3) 4.4 Barrel Optic Ready Legion Grey Cerakote Buy Sig SAUER P226 9mm 4.4in 18rd Semi-Automatic Pistol (226X-9-LEGION) online Sig SAUER P226 9mm 4.4in 18rd Semi-Automatic Pistol (226X-9-LEGION) Buy Sig SAUER P320 Legion 9mm Luger 3.9in 10rd Pistol 320AXGF-9-LEGION-10 online Sig SAUER P320 Legion 9mm Luger 3.9in 10rd Pistol 320AXGF-9-LEGION-10 Buy Sig Sauer Tango-MSR LPVO 1-6x24mm Rifle Scope online Sig Sauer Tango-MSR LPVO 1-6x24mm Rifle Scope

About SI

SI focuses on practical, performance-driven firearm accessories for a wide range of pistols, rifles, and shotguns. Their lineup includes slide adapter plates, latchless charging handles, barrel clamps, compact red dot optics, and dedicated shotgun components, built primarily from aluminum and hardened materials. Products are engineered with attention to fit, function, and ease of installation, aimed at shooters who want reliable upgrades without unnecessary complexity. SI supports competitive, tactical, and recreational shooters by offering parts that address common user needs and enhance firearm ergonomics and capability.

Headquarters

Established

-

Country of Origin

USA

History & Heritage

SI began as an American aftermarket parts maker aimed at providing functional, affordable upgrades and accessories for shooters. Over time the brand expanded its offerings across pistol, rifle, and shotgun platforms, becoming known for practical designs and broad compatibility.

Notable Products

Popular items include charging handles, slide adapter plates, red dot sights, barrel clamps, and shotgun conversion components.

Why Choose SI?

Choose SI for straightforward, well-engineered accessories that improve usability and durability without unnecessary complexity.

Ready to Shop SI?

Choose SI for straightforward, well-engineered accessories that improve usability and durability without unnecessary complexity....

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