Lumen 850 Duo Waist Light

(4 customer reviews)


The Lumen 850 Duo offers versatility, high lumen output, and a wide feature set ready for any adventure. This light features UltrAspire 3D Lighting which casts shadows across uneven surfaces giving you a better understanding of your terrain. The Lumen 850 Duo comes with a headlamp strap allowing the light to clip in and double as a headlamp. Equipped with 3 regular modes, high, medium, low and a red light mode allows complete control over your lumen output. The large power button makes toggling through the setting intuitive and also includes a battery indicator light that when toggled on quickly illuminates green, gold, or red indicating battery level. It can be adjusted up or down in the bracket to your preferred lighting angle. The belt is built with an ErgoFit Waist design that sits comfortably on the body. Open cell foam placed behind the light bracket makes this light comfortable and helps to wick and dissipate moisture. This waist light includes one of our UltrAspire rechargeable 18650 batteries and features a USB Type-C charging port for a very quick charge. Includes a USB Type-C charging cable.


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Out of Stock. Estimated availability mid May 2024


Available on backorder

SKU: UA542BK Category:


  • Aircraft grade aluminum
  • Included headlamp bracket
  • Conical belt
  • Adjustable angle
  • Easy to use performance buckle
  • Large buttons
  • USB Type-C charging port (charging cable included)
  • Breathable mesh
  • Low, medium, high, and blinking modes
  • Sturdy low-profile aluminum bracket included
  • Illuminated battery light indicator
  • 4-11 hour burn time
  • IPX7 Waterproof rating

Weight: 3.8 (107g)

Colors: Black/Red

Sizing Range: 26″-38″


Low Weight™: Lightweight components and materials create an almost unnoticeable on-the-body feel without compromising durability.

Steady Beam™: Prevents eye fatigue by maintaining a steady lumen output that does not dim until the battery is very low.

Race Fit™: Conical shape, fatigue free buckles, and limited stretch elastic ensure a snug and stable fit which promotes a healthy and natural breathing pattern.

Stable Ride™: Proportional weight distribution combined with our conical belt shape create  balanced load and a no-bounce ride.

Fatigue Free™: Intuitive settings, large buttons, and quick release buckles. Easy operation for fatigued minds in extreme circumstances.

AutoCool™: Heat dispersing fins mounted in and around the light passively dissipate heat, keeping the light cool and efficient during heavy use.

Widebeam™: Like daylight. Let your eyes roam freely without adjusting between light and dark areas. Even lighting eliminates headaches and tunnel vision.

Enduralight™: Sturdy construction and aircraft grade aluminum provide better durability and improved hot and cold tolerance while reducing overall weight.

PerfectAngle™: Easily adjust up, straight, or down to suit your terrain. Illuminate your path while keeping your head and body in a natural running position.

Additional information

Weight .69 lbs
Dimensions 5.5 × 3.5 × 6.5 in

4 reviews for Lumen 850 Duo Waist Light

  1. Dandelion Dilluvio-Scott

    I have been using the Lumen 600 for years and recently upgraded to this new version of the 850. As an ultra runner specializing in 100 miler and someone who simply enjoys running all night on my own I have really come to appreciate the illumination ultraspire waist lights offer. This model did not disappoint! I like to use the low or medium setting as my default modes which are plenty bright, but absolutely low how far the high mode can cast light when I’m passing through a region with a higher density of bears or moose. The belt is extremely comfortable and often forget it’s even there. Typically I don’t even take if off until well after sunrise when I’m swapping layers.

  2. TX is hot – run at night Chip

    Where has this been all of my life! Headlamps have a place in this world but the “bouncy” light they give off when running trails is why I tried the 850. I love the broad, steady light it provides – depth perception is so much better. I use it on low or medium, with high reserved for sketchy times. The battery has been great – tested to 4 hours so far. It’s so much more comfortable than a headlamp that I sometimes forget to turn it off after the sun comes up – other runners have to remind me when we pass.

  3. Robert (verified owner)

    Love this belt. Super comfortable, incredible light throw, and coverage. The battery life is unbelievable.
    The advertised battery run times are greatly underestimated.
    I’ve used it for 2 100 mile races and lasted the entire night on one battery for both races.
    11 hrs on 2nd setting (which is super bright) and the light didn’t die, I turned it off at sunrise.

  4. Matt C.

    This light is absolutely awesome. It’s my favorite for early morning runs in the dark. Great for use on the trail or even on the road to help be seen.

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