Buy SI Online
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 226RM9LEGIONR2 P226 9mm 10+1 4.40" Optic Ready Serrated
Sig Sauer P220 Legion .45 ACP 4.4" 8-Rounds
Sig Sauer 8901206 P365-XMACRO 17rd 9mm Magazine Coyote Tan
Sig MCX Rattler 5.56 Pistol 5.5" 30rd. Black
Sig Sauer E225VP4020 22-250Rem 40gr Extreme Expansion Tip 20/Box
Sig Sauer P365-380 Semi-Auto Pistol, Robin's Egg Blue, Nickel Slide, 10-Round
SIG P365-XMACRO 9mm 3.7" 17rd Black Pistol
Sig Sauer 8901182 P365-XMACRO Grip Module 9mm 17rd Mags Manual Safety
SIG SAUER P365 X-Macro Compact 9mm Coyote Brown Grip Module (8901181)
Sig Sauer P365-XMacro Grip Module Black
Sig Sauer MPX Copperhead 9mm Pistol 3.5" Barrel Coyote
Sig Sauer P365-380 Rainbow Titanium Micro-Compact 380ACP 3.1" XRAY-3 OR 10RD
Sig Sauer SOR44102 Romeo 4T Pro 1x20mm Red Dot Sight FDE 65 MOA Ring
Sig Sauer SOR44101 Romeo 4T Pro 1x20mm Red Dot Sight Matte Black
Sig Sauer P365 MS HGA .380 Auto 3.1" Barrel SF Nitron Black XR3 Mod Poly Grip 2-10 Round Mags MA Comp
Sig Sauer AIRT4 Air T4 Scope 1-4x24mm Mil-Dot Reticle Black
Sig Sauer P365-XMACRO 9mm 3.7" 17rd Black
Sig Sauer 8901168 P226 X-Five 9mm 20rd Black Steel Magazine
Sig SAUER P226 XFIVE 20rd 9mm Extended Magazine w/ White Basepad (8901167)
Sig SAUER KILO Canyon 6x22mm Graphite Monocular (SOKCN606)
Sig Sauer Venari 300 Win Mag 180 gr Soft Point Rifle Ammo
Sig Sauer V7MMSP15420 Venari 7mmRemMag 154gr Soft Point 20 Rounds
Sig Sauer Venari 30-06 Springfield 165 gr Soft Point Rifle Ammo
Sig Sauer Venari 270 Win 130 gr Soft Point Ammo
Sig Sauer P365-XMACRO 9mm 3.1" Pistol, 17+1, Optic Ready, XRAY Sights
SIG SAUER Zulu6 HDX 20x42 OIS Image Stabilized FDE Binocular (SOZ6WP20)
SIG Sauer Tango-MSR 1-10x26mm Rifle Scope FFP
Sig Sauer SOK18611 Buckmaster 1800 laser RF 6x22mm Red LED Blk
Sig Sauer P365 X-Series 9mm 3.1in Coyote Brown Slide Assembly
Sig Sauer MPX 35rd 9mm Luger Magazine Black
SIG SAUER WHISKEY6 3-18x44mm 30mm Quadplex SFP Riflescope (SOW63114)
Sig Sauer Whiskey6 3-18x44mm Quadplex Reticle Rifle Scope
Sig Sauer MPX Competition Carbine Semi-Automatic Rifle 9mm Luger
Sig MPX 4.5" 9mm Black Pistol with Aluminum M-Lok Handguard and 35RD Mag
Sig Sauer W365XL-9-BXR3P P365 XL 9mm 3.7" Nitron Semi-Auto Pistol
Sig SAUER LTXG Grip Module Assembly for P320 XSeries (8901005)
Sig Sauer P210 9mm 8rd Steel Magazine
Sig Sauer W220R-45-BSE P220 Elite 45 ACP 4.4" Nitron Semi-Auto Pistol
Sig SAUER Tango-DMR 5-30x56mm Illum FFP MRAD DEV-L 2.0 Riflescope SOTD65112
Sig Sauer Tango-DMR 5-30x56mm 34mm SF Illuminated FFP MOA DEV-L
Sig SAUER Tango-DMR 3-18x44 34mm FFP MRAD Milling 2.0 Riflescope SOTD63112
Sig Sauer Tango-DMR 3-18x44mm 34mm SF Illuminated FFP MOA Mill
Sig Sauer Whiskey6 Black 3-18x44mm Rifle Scope MOA Milling Hunter 2.0 Reticle
Sig SAUER Whiskey6 3-18x44mm MOA Milling Hunter 2.0 Riflescope SOW63111
SIG Sauer P320-XFIVE DH3 9mm Pistol Coyote Tan
Sig Sauer SOZ6WP16 ZULU6 HDX 16x42mm Binoculars, Image Stabilized, IPX7
Sig SAUER ZULU6 HDX OIS 12x42mm Binocular FDE
Sig SAUER ZULU6 HDX OIS 10x30mm Binocular FDE
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.
SIG SAUER 322C-ROSE-RS P322 Rose 22 LR 4" Black Anodize Semi
SilencerCo Sparrow 22 Rimfire Suppressor 22LR 5.08" Stainles
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...
Ready to Shop SI?
Choose SI for straightforward, well-engineered accessories that improve usability and durability without unnecessary complexity....
Browse All Products