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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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2,382
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Founded
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All SI Products (2,382)

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BP1003 online Sig Sauer 9mm Luger Unprimed Brass Handgun Cartridge Cases 100ct - BP1003 Buy Sig Sauer Unprimed Brass Handgun Cartridge Cases .380 Auto 100/ct online Sig Sauer Unprimed Brass Handgun Cartridge Cases .380 Auto 100/ct Buy Sig Sauer 308 Win 175gr OTM Ammo 20rds E308M2-20 online Sig Sauer 308 Win 175gr OTM Ammo 20rds E308M2-20 Buy Sig Sauer Elite Copper Hunting .308 Win 150gr Ammo online Sig Sauer Elite Copper Hunting .308 Win 150gr Ammo Buy Sig Sauer Romeo 4 T Red Dot Sight 1x20mm Black 2 MOA 7075 Aluminum online Sig Sauer Romeo 4 T Red Dot Sight 1x20mm Black 2 MOA 7075 Aluminum Buy ROMEO4S Ballistic PLX SOL - 0.5 MOA Adjustment Grip online ROMEO4S Ballistic PLX SOL - 0.5 MOA Adjustment Grip Buy Sig Sauer SRD22X 22 LR Suppressor 5.8 in Titanium 1/2x28 Direct Thread online Sig Sauer SRD22X 22 LR Suppressor 5.8 in Titanium 1/2x28 Direct Thread Buy Sig Sauer 1911 Pistol 10mm 8 Round Black Detachable Magazine online Sig Sauer 1911 Pistol 10mm 8 Round Black Detachable Magazine Buy Sig Sauer SOK20001 Tripod Adapter Sleeve Black Aluminum for Kilo 2000 Series online Sig Sauer SOK20001 Tripod Adapter Sleeve Black Aluminum for Kilo 2000 Series Buy Sig Sauer Juliet4 Magnifier 4x24mm Black Quick Release Mount online Sig Sauer Juliet4 Magnifier 4x24mm Black Quick Release Mount Buy Sig Sauer MAG-MOD-F-43-18 P320 40/357 18-Round Magazine online Sig Sauer MAG-MOD-F-43-18 P320 40/357 18-Round Magazine Buy Sig Sauer P320 RSA-320F-9 Full Size 9mm Luger Recoil Spring Assembly online Sig Sauer P320 RSA-320F-9 Full Size 9mm Luger Recoil Spring Assembly Buy Sig Sauer P320 RSA-320F-4035745 Full Size Recoil Spring Assembly online Sig Sauer P320 RSA-320F-4035745 Full Size Recoil Spring Assembly Buy Sig SAUER P320/P250 .357 SIG Full Broached Black Small Barrel - BBLMODF357 online Sig SAUER P320/P250 .357 SIG Full Broached Black Small Barrel - BBLMODF357 Buy Sig Sauer P320/P250 Compact 3.9" 40 S&W DLC Broached Barrel - Black Nitron Finish online Sig Sauer P320/P250 Compact 3.9" 40 S&W DLC Broached Barrel - Black Nitron Finish Buy Sig SAUER P320/P250 .40SW Full Broached Black Small Barrel online Sig SAUER P320/P250 .40SW Full Broached Black Small Barrel Buy SigTac P250/P320 FullSize Magazine 9mm 21 Rounds Md: MAG-MOD-F-9-21 online SigTac P250/P320 FullSize Magazine 9mm 21 Rounds Md: MAG-MOD-F-9-21 Buy Sig Sauer MPX 9mm 10-Round Magazine Gen2 Keymod online Sig Sauer MPX 9mm 10-Round Magazine Gen2 Keymod Buy Sig P938 Emperor Scorpion Micro-Compact: Steel Barrel, PVD FDE, SigLite, G-10 Grip online Sig P938 Emperor Scorpion Micro-Compact: Steel Barrel, PVD FDE, SigLite, G-10 Grip Buy Sig P238 Emperor Scorpion Micro-Compact: Stainless Slide, FDE Frame, G-10 Grips online Sig P238 Emperor Scorpion Micro-Compact: Stainless Slide, FDE Frame, G-10 Grips Buy Sig Sauer P320 Compact 9mm Semi-Auto Pistol Black online Sig Sauer P320 Compact 9mm Semi-Auto Pistol Black Buy Sig Sauer M11-A1 Compact 9MM Pistol: 3.9" Barrel, Alloy, Nitron, SIGLITE Sights, 15Rd, SRT, 3 Mags online Sig Sauer M11-A1 Compact 9MM Pistol: 3.9" Barrel, Alloy, Nitron, SIGLITE Sights, 15Rd, SRT, 3 Mags

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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