The Sig Sauer Foxtrot4R is a compact mounted light engineered for pistols and carbines that demand serious output in a small package. Built around a white LED that delivers 1350 lumens and 33,000 candela, this rail-mounted light puts bright, usable illumination exactly where you need it—whether you're running a home-defense setup, training at the range, or building a duty gun. The aluminum construction keeps weight down to just 4.1 ounces with battery, so it won't throw off your gun's balance or handling.
What sets the Foxtrot4R apart is its flexibility. It ships with two rail interface inserts: one for standard MIL-STD 1913 Picatinny rails, and another for pistols with proprietary rail designs. The 4-position sliding inserts let you dial in the exact fit and position on your firearm. Control is intuitive—ambidextrous activation paddles give you momentary, latching, and threshold modes, all user-programmable so you can tailor the light to your workflow. IPX-7 waterproofing means it'll handle rain, sweat, and the occasional dunking without quitting on you.
Runtime is honest: up to one hour on a full charge using the included 18350 Li-ion rechargeable battery. Two batteries ship in the box, so you can keep one in the gun and have a fresh spare charged and ready. At 3.47 inches long and just under an inch and a half tall, it tucks tight to the rail without adding bulk—ideal if you're running a compact carry gun or a short-barreled rifle where every millimeter counts.
| Peak Lumens | 1350 |
| Peak Candela | 33,000 |
| Run Time | Up to 1 hour |
| Battery Type | 1× 18350 Li-ion rechargeable (2× included) |
| Waterproof Rating | IPX-7 |
| Length | 3.47" |
| Height | 1.49" |
| Width | 1.18" |
| Weight (with battery) | 4.1 oz |
The Foxtrot4R comes with two rail inserts: one for standard MIL-STD 1913 Picatinny rails (found on most modern tactical pistols and carbines), and a second insert for pistols with non-standard rail designs. The 4-position sliding inserts also let you adjust the mounting position for a custom fit.
The ambidextrous paddles offer momentary (press to light, release to dark), latching (tap once to stay on, tap again to turn off), and threshold mode. You can program which mode you prefer, so the light responds exactly how you want it to.
Runtime is up to one hour at full brightness on a single 18350 Li-ion rechargeable battery. Two batteries are included in the package, so you can keep a spare charged and ready to swap.
Yes. The Foxtrot4R carries an IPX-7 waterproof rating, so it will function reliably in rain, wet environments, and even brief submersion.
Sig Sauer
Sig Sauer
