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SI designs rugged, user-focused firearm components and optics. They make accessories like slide plates, charging handles, barrel clamps, red dots, and shotgun parts.
All SI Products (2,381)
Sig SAUER INC 9MM LUGER 10+1 3.1 Nitron Stainless Steel Slide
Sig SAUER 365X-9-SXR3P P365X 9mm 3.1" Stainless Semi-Auto Pistol
Sig SAUER 365-9-SXR3P P365 9mm 3.1" Stainless Semi-Auto Pistol
Sig SAUER 365X-9-CTXR3P P365X 9mm 3.1" Two-Tone Coyote Semi-Auto Pistol
Sig SAUER 365-9-CTXR3P P365 9mm 3.1" Two-Tone Coyote Semi-Auto Pistol
Sig Sauer P226 9mm Magazine 18RD Steel Oxide Finish MPN 8901991
Sig Sauer Hexium 7.62mm TI Suppressor 7.62mm Titanium Hub Taper Direct Mount 1/2-28
Sig Sauer Hexium 5.56mm INC Suppressor 5.56mm Inconel Hub Taper Direct Mount 1/2-28
Sig Sauer Hexium 5.56mm TI Suppressor 5.56mm Titanium Hub Taper Direct Mount 1/2-28
Sig Sauer Tin Can .30 TI Suppressor .30 Cal Titanium Hub Taper Direct Mount 5/8-24
Sig Sauer P211-GTO Blackout Handgun 9mm Luger 21(2)&23(1)rd Magazines 4.4 Compensated Barrel Optic Ready SAO
Sig Sauer Electro-Optics SOK8K702 KILO8K ABS Gen II 7x25mm 8000 yds Max Distance, 304x256 Active Matrix OLED Display, Flat Dark Earth
Sig Sauer NG762CQDCOY SLH 7.62mm 1.67" Black Inconel
Sig Sauer P211-GTO Handgun 9mm Luger 10rd Magazines(3) 4.4 Compensated Barrel Optic Ready SAO
Sig ROMEO-RS COMPACT 3MOA RED DOT ROSE
Sig Sauer Endure .30 TI Suppressor .30 Cal Titanium Hub Taper Direct Mount 5/8-24
Sig Sauer P211-GTO Handgun 9mm Luger 21(2)&23(1)rd Magazines 4.4 Compensated Barrel Optic Ready SAO
Sig Sauer P226X Legion 9MM 4.4in Black 18- Semi-Auto Pistol
Sig Sauer P365 LUXE AXG Handgun .380 Auto 12rd Magazine(3) 3.1 Compensated Barrel Black Finish
Sig Sauer P365-FLUX Handgun 9mm Luger 21(2)17(1)&25(1)rd Magazines 6 Barrel Brace w/TacKit
Sig Sauer P365-FLUX Handgun 9mm Luger 21(2)&17(1)rd Magazines 6 Barrel Brace
Sig Sauer Tango-MRS Compact Rifle Scope 1-6x24 30mm SFP BDC6 Illum. Black with Romeo 1 Red Dot
Sig Sauer P226 XCarry Legion Handgun 9mm Luger 18rd Magazines(3) 3.8 Barrel SAO Red Dot Legion Grey Cerakote
Sig Sauer P226-X Legion SAO Handgun 9mm Luger 18rd Magazines(3) 4.4 Barrel Legion Grey Cerakote w/Optic
Sig Sauer SORMDC60 26MM Black Red Dot 12 Settings
Sig Sauer SORMDC30 26MM Black Red Dot 12 Settings
Sig Sauer P365 Axg Legion 9MM 3.1in Gray 17 1 Semi-Auto Pistol
Sig Sauer RM400 223 5.56 16in Black Optics Ready Rifle
Sig Sauer SOK22606 22MM Graphite Red LED Ballistic Rangefinder
Sig SAUER P226 X-Series Legion 9mm 4.4in 3x18rd Legion Gray DA/SA Pistol
Sig Sauer Romeo-RS Compact Footprint Green Dot 6 MOA Dot Black
SIG SAUER Romeo-RS Compact 3 MOA Green Dot Reticle Reflex Sight (SOR02180)
Sig Sauer SOR02101 Romeo-RS 1x24mm 2 MOA Red Dot/32 MOA Circle Reticle
Sig SAUER Romeo-RS Pro 6 MOA Green Dot Reticle Black Reflex Sight SOR02090
Sig Sauer ROMEO-RS PRO Footprint 3 MOA Green Dot Sight - Black
Sig Sauer Romeo-RS Pro Red Dot Circle Dot Clear
Sig Sauer Bravo6T-BDX Rifle Scope 5-30x56mm 35mm FFP MRAD DEV-L 2.0 Illum Black
Sig Sauer Bravo6T-BDX Rifle Scope 3-18x44mm 35mm FFP MRAD Milling 2.0 Illum Black
Sig Sauer TANGO TANGOMSR 1-6X24 SFP Hellfire MOA Scope Black
Sig Sauer SOTMC11002 Tango MSR 1.535 Mount FFP Illuminated Matte Black
Sig Sauer SOTMC11002 TANGO 1-10x24 FFP Scope, 30mm Tube, BDC 10 Reticle
Sig Sauer 1911-XCARRY Stainless Handgun .45 ACP 8rd Magazine(2) 4.2 Barrel Optic Ready
Sig SAUER 365XCA-9-COMP-RXSL-10 P365 X-MACRO COMP 9mm 3.1" Nitron Semi-Auto
Sig SAUER 365XCA-9-COMP-RXSL P365 X-MACRO COMP 9mm 3.1" Nitron Semi-Auto
Sig SAUER 365XCA-9-BXR3-RXSL-10 P365 X-MACRO 9mm 3.7" Nitron Semi-Auto
Sig SAUER 365XCA-9-BXR3-RXSL P365 X-MACRO 9mm 3.7" Nitron Semi-Auto
Sig SAUER 365X-9-BXR3-RXSL P365X ROMEO-X 9mm 3.1" Nitron Semi-Auto
Sig Sauer TANGO SOTMC81000 1-8x24 30mm Tube Illuminated BDC Reticle Black
About SI
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.
Hot SI Items June 2026
Trending right now based on the last 30 days of TheGunDock orders + page views.
SilencerCo Sparrow 22 Rimfire Suppressor 22LR 5.08" Stainles
SIG SAUER 322C-ROSE-RS P322 Rose 22 LR 4" Black Anodize Semi
Sig Sauer W365XL-9-BXR3P-MS P365 XL 9mm 3.7" Nitron Semi-Aut
Sig Sauer Tango-MRS Compact Rifle Scope 1-6x24 30mm SFP BDC6
Sig Sauer Cross Sawtooth Rifle 6.5 PRC 22 inch Moss Green Fo
Sierra Bullets 4540C 7mm 0.284 Caliber 140 Grain Tipped Boat
SilencerCo AC1278 ASR Black Nitride 9/16"x24 LH Threads 30 C
Sig Sauer W365XL-9-BXR3P-RXX P365 XL Romeo-X 9mm 3.7" Nitron
Shop SI Products
Sig SAUER MCX-SPEAR 6.8x51mm SBR 13in Semi-Auto Rifle RSPEAR
SilencerCo Sparrow 22 Rimfire Suppressor 22LR 5.08" Stainles
Sig Sauer P320 FLUX 9MM 3.9" 30RD Legion 320
Sig Sauer SLH300TIQD 300 Blackout Titanium Suppressor
SilencerCo Velos LBP 5.56 NATO/.223 4.76 In Low Back-Pressur
SIG SAUER MCX Spear SBR 7.62x51mm 13" Nitride NFA
Sig Sauer P365X Macro Tacops 9mm 3.7" 17rd Pistol
Sinclair INTERNATIONAL DIAL INDICATOR .001
Sig Sauer ROMEO1 Black Shroud Kit SOR1SK001: Medium Size, Ne
Sig Sauer 8900823 LTXG Grip Module Laser Engraved P320-X Car
Sig Sauer MCX-SPEAR LT AR Conversion Kit 5.56 NATO 11.5" Bla
Sig SAUER MCX 5.56 NATO 16in 30rd IR Cerakote FDE Rifle RMCX
SI News & Articles
Firearm Shipping Restrictions by State (2026 Update)
State-by-state guide to firearm and ammunition shipping for online buyers and FFL dealers. Current as of May 2026. Cover...
Damaged in Transit: How TheGunDock Handles Shipping Claims on Firearms and Ammo
When a firearm or ammo shipment arrives damaged, the claim process matters. TheGunDock walks through what to do, what we...
The Springfield KUNA: Roller-Delayed 9mm Pistol That's Shaking Up the PDW Market
The Springfield Armory KUNA — a roller-delayed 9mm pistol built in partnership with Croatia's HS Produkt — has becom...
The Strait of Hormuz: 2,500 Years of Trade, Arms, and Conflict
A twenty-one-mile-wide choke point has shaped the movement of goods — and weapons — across half the ancient and mode...
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Choose SI for straightforward, well-engineered accessories that improve usability and durability without unnecessary complexity....
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