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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
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2,384
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Founded
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All SI Products (2,384)

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Laser Boresighter Cartr Buy Sightmark SM39004 Red Laser Boresight for .7mm, .264, .338 Caliber online Sightmark SM39004 Red Laser Boresight for .7mm, .264, .338 Caliber Buy Sightmark SM39003 Red Laser Boresight for .30-06, .270, .25-06 Brass online Sightmark SM39003 Red Laser Boresight for .30-06, .270, .25-06 Brass Buy Sightmark SM39002 Red Laser Boresight 7.62x39mm Brass with Case & Battery online Sightmark SM39002 Red Laser Boresight 7.62x39mm Brass with Case & Battery Buy Sightmark .223 Rem Premium Laser Boresight online Sightmark .223 Rem Premium Laser Boresight Buy Sig Sauer 365X-9-BXR3P 9MM Pistol, 3.7" Barrel, FDE, XRAY3, 12 Rounds online Sig Sauer 365X-9-BXR3P 9MM Pistol, 3.7" Barrel, FDE, XRAY3, 12 Rounds Buy Sig Sauer 300-252-0408-11 P365X 9MM 3.1" Barrel, Optic Ready, 17 Rds, White online Sig Sauer 300-252-0408-11 P365X 9MM 3.1" Barrel, Optic Ready, 17 Rds, White Buy Sig Sauer 365X-9-BXR3P 9MM Pistol, 3.7" Barrel, XRAY3 Sights, 12 Rounds online Sig Sauer 365X-9-BXR3P 9MM Pistol, 3.7" Barrel, XRAY3 Sights, 12 Rounds Buy Sig Sauer 365X9BXR3RXXISLANDGB 9MM 3.1" Barrel 12rd Romeo-X Optic Nitron online Sig Sauer 365X9BXR3RXXISLANDGB 9MM 3.1" Barrel 12rd Romeo-X Optic Nitron Buy Sig SHARK COAST TACTICAL FDE 365XR3RXX W ROMEO online Sig SHARK COAST TACTICAL FDE 365XR3RXX W ROMEO Buy Sig SHARK COAST TACTICAL ODG 365XR3RXX W ROMEO online Sig SHARK COAST TACTICAL ODG 365XR3RXX W ROMEO Buy Sig Sauer 300-258-0421-64 XMacro 9MM 3.1" Barrel Optic Ready 17 Rds online Sig Sauer 300-258-0421-64 XMacro 9MM 3.1" Barrel Optic Ready 17 Rds Buy Sig Sauer 300-258-0421-14 XMacro 9MM 3.1" Optic Ready 17 Rds Dayglow Green online Sig Sauer 300-258-0421-14 XMacro 9MM 3.1" Optic Ready 17 Rds Dayglow Green Buy Sig Sauer 300-258-0421-04 XMacro 9MM 3.1" Optic Ready, 17 Rounds, Black online Sig Sauer 300-258-0421-04 XMacro 9MM 3.1" Optic Ready, 17 Rounds, Black Buy Sig Sauer 300 252 0408 64 9mm Optics Ready Blue Finish online Sig Sauer 300 252 0408 64 9mm Optics Ready Blue Finish Buy Sig Sauer 300-252-0408-14 P365X 9MM 3.1" Barrel, 17 Rds, Optic Ready online Sig Sauer 300-252-0408-14 P365X 9MM 3.1" Barrel, 17 Rds, Optic Ready Buy Sig Sauer 300-252-0408-04 P365X 9MM 3.1" Barrel 17 Rds Optic Ready Black online Sig Sauer 300-252-0408-04 P365X 9MM 3.1" Barrel 17 Rds Optic Ready Black Buy Sig Sauer P365 XMacro 9MM 3.7" Gold Threaded Barrel Galactic June Bug Optic Ready Sub-Compact Pistol with XRAY3 Sights, 17Rd Magazines - 365 online Sig Sauer P365 XMacro 9MM 3.7" Gold Threaded Barrel Galactic June Bug Optic Ready Sub-Compact Pistol with XRAY3 Sights, 17Rd Magazines - 365 Buy Sig Sauer 365XCA-9-COMP P365 XMacro 9MM Pistol, 3.1" Barrel, 17 Rds online Sig Sauer 365XCA-9-COMP P365 XMacro 9MM Pistol, 3.1" Barrel, 17 Rds Buy Sig Sauer 300231040020 Cypress Raptor P365, Green Slide, FDE Frame online Sig Sauer 300231040020 Cypress Raptor P365, Green Slide, FDE Frame Buy Sig Sauer 300231041520 Cypress Raptor P365 Green Slide FDE Frame online Sig Sauer 300231041520 Cypress Raptor P365 Green Slide FDE Frame Buy Sig Sauer 300231041920 P365 Cypress Raptor Green/FDE by Shark Coast Tactical online Sig Sauer 300231041920 P365 Cypress Raptor Green/FDE by Shark Coast Tactical Buy Sig Sauer 300231041120 Cypress Raptor P365X, Green Slide, Romeo-X Red Dot online Sig Sauer 300231041120 Cypress Raptor P365X, Green Slide, Romeo-X Red Dot Buy Sig Sauer 300229041056 P365X Supersonic Cerakote Optic-Ready Pistol online Sig Sauer 300229041056 P365X Supersonic Cerakote Optic-Ready Pistol Buy Sig Sauer 300174041903 P365 XMACRO Optic-Ready Brown Slide, Gold Barrel online Sig Sauer 300174041903 P365 XMACRO Optic-Ready Brown Slide, Gold Barrel Buy Sig Sauer 300174041103 P365X Debacle, Optic-Ready, Gold Barrel, Cerakote Brown online Sig Sauer 300174041103 P365X Debacle, Optic-Ready, Gold Barrel, Cerakote Brown Buy Sig Sauer 300174041503 P365 XMACRO Optic-Ready Brown Slide, Gold Barrel online Sig Sauer 300174041503 P365 XMACRO Optic-Ready Brown Slide, Gold Barrel Buy Sig Sauer 300174041003 P365X Debacle, Optic-Ready, Brown Cerakote, Grey Frame online Sig Sauer 300174041003 P365X Debacle, Optic-Ready, Brown Cerakote, Grey Frame Buy Sig Sauer 300226040022 P365 Peach Fuzz Blue Slide Pink Frame Optic Cut online Sig Sauer 300226040022 P365 Peach Fuzz Blue Slide Pink Frame Optic Cut Buy Sig Sauer 300174041303 P365X Debacle, Brown Cerakote, RomeoX Red Dot online Sig Sauer 300174041303 P365X Debacle, Brown Cerakote, RomeoX Red Dot Buy Sig Sauer 3001740413032 P365X Shark Coast Tactical Debacle, Red Dot, Gold Barrel online Sig Sauer 3001740413032 P365X Shark Coast Tactical Debacle, Red Dot, Gold Barrel Buy Sig Sauer P365 Fuse Semi-automatic Polymer Frame Pistol Compact 9MM 4.3" online Sig Sauer P365 Fuse Semi-automatic Polymer Frame Pistol Compact 9MM 4.3" Buy Sig Sauer P365 Fuse Semi-automatic Polymer Frame Pistol Compact 9MM 4.3" online Sig Sauer P365 Fuse Semi-automatic Polymer Frame Pistol Compact 9MM 4.3" Buy Sig Sauer P365 Fuse Semi-automatic Polymer Frame Pistol Compact 9MM 4.3" online Sig Sauer P365 Fuse Semi-automatic Polymer Frame Pistol Compact 9MM 4.3" Buy Sig Sauer P365 Fuse Semi-automatic Polymer Frame Pistol Compact 9MM 4.3" online Sig Sauer P365 Fuse Semi-automatic Polymer Frame Pistol Compact 9MM 4.3" Buy Sig P365X 9MM 3.1" 12RD ROBINS EGG online Sig P365X 9MM 3.1" 12RD ROBINS EGG Buy Sig Sauer P365X Striker Fired Sub-Compact Polymer Frame Pistol Subcompact online Sig Sauer P365X Striker Fired Sub-Compact Polymer Frame Pistol Subcompact Buy Sig Sauer 8900789 P320 9mm 3.6" Gold Titanium-Nitride Barrel online Sig Sauer 8900789 P320 9mm 3.6" Gold Titanium-Nitride Barrel Buy Sig Sauer 8900777 P365XL 9mm 3.7" Gold Titanium-Nitride Barrel online Sig Sauer 8900777 P365XL 9mm 3.7" Gold Titanium-Nitride Barrel Buy Sig P365-XMacro Freedom Handgun 9mm luger 17rd Magazines(2) 3.7 Barrel Two-Tone White on Black Optic online Sig P365-XMacro Freedom Handgun 9mm luger 17rd Magazines(2) 3.7 Barrel Two-Tone White on Black Optic Buy Sig SAUER 1911XR-45-TWXR3-TP 1911 X Series 45 ACP 5.0" White Cerakote Semi-Auto Pistol online Sig SAUER 1911XR-45-TWXR3-TP 1911 X Series 45 ACP 5.0" White Cerakote Semi-Auto Pistol Buy Sig SAUER 1911XCA-45-TWXR3-TP 1911 X Carry 45 ACP 4.2" White Cerakote Semi-Auto Pistol online Sig SAUER 1911XCA-45-TWXR3-TP 1911 X Carry 45 ACP 4.2" White Cerakote Semi-Auto Pistol Buy Sig 365X9GXR3P P365 9MM 3.1 OR 12R MSGRN online Sig 365X9GXR3P P365 9MM 3.1 OR 12R MSGRN Buy Sig Sauer P365 9mm 3.1" Barrel 10-Round Magazine Green online Sig Sauer P365 9mm 3.1" Barrel 10-Round Magazine Green Buy Sig Sauer P365 AXG Fuse 9mm 4.3 In 21-Rounds Nitron Black/Coyote online Sig Sauer P365 AXG Fuse 9mm 4.3 In 21-Rounds Nitron Black/Coyote

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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