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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 8900980 P365 Slide Completion Kit 9mm Corrosion Resistant
Sig Sauer 8900979 P320 Slide Parts Kit 9mm/357Sig Steel Components
Sig Sauer P320 9mm Luger Coyote Brown Stainless Steel Optic Ready Slide
Sig Sauer 8900952 P320 Pro-Cut Slide 9mm Coyote Brown PVD XRAY3 Sights
Sig Sauer 8900951 P320 Subcompact 9mm Pro-Cut Slide, Optic Ready, Coyote
Sig Sauer 8900950 P320 9mm Optic Ready Slide Black PVD XRAY3 Sights
Sig Sauer 8900949 P320 9mm Optic Ready Slide Black PVD XRAY3 Sights
Sig Sauer 8900948 P320 9mm Optic Ready Slide Black PVD XRAY3 Sights
Sig Sauer M400 X-Series 5.56 NATO 16" 30+1 Black Magpul SL-K Stock Flat Match Trigger
SIG SAUER Buckmaster 10x42mm Roof Prism Binoculars
Sig Sauer 8900917 Safety Parts Kit 9mm Luger/380 ACP Sig P365/P365X/XL Gold
Sig Sauer P365XL 9mm 3.7in Barrel Black Manual Safety 10rd Capacity
Sig Sauer P365 XL 9mm Luger Pistol 10 Rounds Black
Sig Sauer P365X 9mm 3.1 in Barrel Black Manual Safety 10-Round
Sig Sauer P365X Micro-Compact 9mm Pistol with X-RAY3 Sights
Sig Sauer P365X 9mm Luger Micro-Compact Pistol, 3.10" Barrel, Optic Ready/Serrated Slide, Black Frame, Polymer Grips
Sig Sauer P365X 9mm Luger Micro-Compact Pistol
SIG SAUER P320 XFull 9mm 4.7" Barrel Black XRay3 Optic Ready
Sig Sauer P320 XFull 9MM 4.7in Barrel Stainless Steel 17rd Striker Fired
Sig Sauer P320 XCompact 9mm Luger 3.60" Barrel Black Optic Ready/Serrated Slide Stainless Frame XCompact Polymer Grips
Sig Sauer P320 XCompact 9mm 3.6in Black 15rd Striker Fired Pistol
Sig SAUER Foxtrot365XR 550 Lumens Pistol Light (SOF365X1)
Sig SAUER P220 Legion Full 10mm 5in DA/SA X-RAY3 Day/Night Sight Pistol
Sig Sauer P220 Legion SAO .45ACP 4.4" Gray G10 X-Ray3 8rd
Sig Sauer P220 Legion Series Semi-Automatic Pistol .45 ACP
Sig Sauer P226 XFive 9mm 5in Bull Barrel Stainless 20rd Single Action
Sig Sauer P226X59CLASSIC 9mm SAO 5" SS Optic Cut Hogue Cocobolo Grip
Sig Sauer Buckmaster 1" High Black Aluminum Hunting Scope Rings
Sig SAUER Buckmasters 1in Medium 0.94in Matte Black Scope Rings (SOA10034)
Sig Sauer Buckmaster 1" Low Scope Ring Set
Sig Sauer Romeo2 Red Circle Dot Reflex Sight 1x30mm
Sig MPX GEN II Air Rifle .177 Cal CO2 30rd Black
Sig SAUER MCX Gen 2 .177 Cal 17.7in 30rd Blk Air Rifle (AIR-MCX-177-G2-BLK)
Sig Sauer 8900823 LTXG Grip Module Laser Engraved P320-X Carry Gray
Sig Sauer P365AXG Legion 9MM 17-Round Magazine Black
Sig Sauer KILO3K 6x22 Rangefinding Monocular OLED Display Green
Sig Sauer SOR44002 ROMEO4XT-PRO 1x20mm Red Dot Sight FDE 0.5MOA M1913
Sig Sauer SOR44001 Romeo4XT-Pro Red Dot Sight 1x20mm 0.5MOA Black
Sig SAUER SigMPX 9mm 20rd Thril Black Rifle Magazine (8900828)
SIG Sauer 8900746 P322 .22 LR 10-Round Black Polymer Magazine
Sig MCX-SPEAR LT 7.62x39mm 16" 28rd Folding Stk M-LOK Coyote
Sig Sauer SOR2M103 Universal Mount Low Profile Black Stainless Steel 6.3"
Sig Sauer P320 XCarry Medium Grip Module: Laser-Stippled, Polymer, Black
Sig Sauer P365 X-MACRO Magazine 9mm 17rd Blued Steel
Sig Sauer SOR2M102 Romeo2 Adapter Plate Black Glock MOS Handgun
Sig Sauer 8900791 P320 9mm 4.7" Gold Nitride Barrel for Full-Size Models
Sig Sauer P320 Compact 8900790 - 9mm Luger, 3.90" Barrel, Gold Titanium-Nitride Finish
Sig Sauer 8900789 P320 Subcompact 9mm Luger 3.7" Gold Barrel Non-Threaded
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...
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