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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 (2,384)
Sightmark SM39008 Red Laser Boresight 20 Gauge Brass with Battery Pack
Sightmark 12GA Boresight - Precision Laser Alignment Tool
Sightmark SM39006 Boresight 300 Win Mag Red Laser Brass 632-650nM
Sightmark SM39005 243 Cal. Laser Boresighter Cartr
Sightmark SM39004 Red Laser Boresight for .7mm, .264, .338 Caliber
Sightmark SM39003 Red Laser Boresight for .30-06, .270, .25-06 Brass
Sightmark SM39002 Red Laser Boresight 7.62x39mm Brass with Case & Battery
Sightmark .223 Rem Premium Laser Boresight
Sig Sauer 365X-9-BXR3P 9MM Pistol, 3.7" Barrel, FDE, XRAY3, 12 Rounds
Sig Sauer 300-252-0408-11 P365X 9MM 3.1" Barrel, Optic Ready, 17 Rds, White
Sig Sauer 365X-9-BXR3P 9MM Pistol, 3.7" Barrel, XRAY3 Sights, 12 Rounds
Sig Sauer 365X9BXR3RXXISLANDGB 9MM 3.1" Barrel 12rd Romeo-X Optic Nitron
Sig SHARK COAST TACTICAL FDE 365XR3RXX W ROMEO
Sig SHARK COAST TACTICAL ODG 365XR3RXX W ROMEO
Sig Sauer 300-258-0421-64 XMacro 9MM 3.1" Barrel Optic Ready 17 Rds
Sig Sauer 300-258-0421-14 XMacro 9MM 3.1" Optic Ready 17 Rds Dayglow Green
Sig Sauer 300-258-0421-04 XMacro 9MM 3.1" Optic Ready, 17 Rounds, Black
Sig Sauer 300 252 0408 64 9mm Optics Ready Blue Finish
Sig Sauer 300-252-0408-14 P365X 9MM 3.1" Barrel, 17 Rds, Optic Ready
Sig Sauer 300-252-0408-04 P365X 9MM 3.1" Barrel 17 Rds Optic Ready Black
Sig Sauer P365 XMacro 9MM 3.7" Gold Threaded Barrel Galactic June Bug Optic Ready Sub-Compact Pistol with XRAY3 Sights, 17Rd Magazines - 365
Sig Sauer 365XCA-9-COMP P365 XMacro 9MM Pistol, 3.1" Barrel, 17 Rds
Sig Sauer 300231040020 Cypress Raptor P365, Green Slide, FDE Frame
Sig Sauer 300231041520 Cypress Raptor P365 Green Slide FDE Frame
Sig Sauer 300231041920 P365 Cypress Raptor Green/FDE by Shark Coast Tactical
Sig Sauer 300231041120 Cypress Raptor P365X, Green Slide, Romeo-X Red Dot
Sig Sauer 300229041056 P365X Supersonic Cerakote Optic-Ready Pistol
Sig Sauer 300174041903 P365 XMACRO Optic-Ready Brown Slide, Gold Barrel
Sig Sauer 300174041103 P365X Debacle, Optic-Ready, Gold Barrel, Cerakote Brown
Sig Sauer 300174041503 P365 XMACRO Optic-Ready Brown Slide, Gold Barrel
Sig Sauer 300174041003 P365X Debacle, Optic-Ready, Brown Cerakote, Grey Frame
Sig Sauer 300226040022 P365 Peach Fuzz Blue Slide Pink Frame Optic Cut
Sig Sauer 300174041303 P365X Debacle, Brown Cerakote, RomeoX Red Dot
Sig Sauer 3001740413032 P365X Shark Coast Tactical Debacle, Red Dot, Gold Barrel
Sig Sauer P365 Fuse Semi-automatic Polymer Frame Pistol Compact 9MM 4.3"
Sig Sauer P365 Fuse Semi-automatic Polymer Frame Pistol Compact 9MM 4.3"
Sig Sauer P365 Fuse Semi-automatic Polymer Frame Pistol Compact 9MM 4.3"
Sig Sauer P365 Fuse Semi-automatic Polymer Frame Pistol Compact 9MM 4.3"
Sig P365X 9MM 3.1" 12RD ROBINS EGG
Sig Sauer P365X Striker Fired Sub-Compact Polymer Frame Pistol Subcompact
Sig Sauer 8900789 P320 9mm 3.6" Gold Titanium-Nitride Barrel
Sig Sauer 8900777 P365XL 9mm 3.7" Gold Titanium-Nitride Barrel
Sig P365-XMacro Freedom Handgun 9mm luger 17rd Magazines(2) 3.7 Barrel Two-Tone White on Black Optic
Sig SAUER 1911XR-45-TWXR3-TP 1911 X Series 45 ACP 5.0" White Cerakote Semi-Auto Pistol
Sig SAUER 1911XCA-45-TWXR3-TP 1911 X Carry 45 ACP 4.2" White Cerakote Semi-Auto Pistol
Sig 365X9GXR3P P365 9MM 3.1 OR 12R MSGRN
Sig Sauer P365 9mm 3.1" Barrel 10-Round Magazine Green
Sig Sauer P365 AXG Fuse 9mm 4.3 In 21-Rounds Nitron Black/Coyote
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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