Men's Avid Ultralight K4 Pant
Men's Avid Ultralight K4 Pant
Men's Avid Ultralight K4 Pant
Men's Avid Ultralight K4 Pant
Men's Avid Ultralight K4 Pant
Men's Avid Ultralight K4 Pant
Men's Avid Ultralight K4 Pant
Men's Avid Ultralight K4 Pant
Men's Avid Ultralight K4 Pant
Men's Avid Ultralight K4 Pant
Men's Avid Ultralight K4 Pant
Men's Avid Ultralight K4 Pant
Men's Avid Ultralight K4 Pant
Men's Avid Ultralight K4 Pant
Men's Avid Ultralight K4 Pant

Men's Avid Ultralight K4 Pant



Rustic Green
Manatee Grey
Fit: Standard
Size & Fit Guide

This is a clearance item. All sales are final.



Beyond System Layer 4


Ultralightweight, Highly Flexible, Treated for Comfort, Designed for Layering

Performance Fit

Low-profile design with an elastic waistband and tapered cuffs improves mobility and ease of layering.


Ultralightweight softshell and a streamlined fit combine to ensure easy stowing when not in use.

Double-Treated Fabric

Clear outer shell coating softens hand feel, and a DWR finish provides weather-resistant protection.

Multi-Season Versatility

The Men’s Avid Ultralight K4 Pant is a streamlined alternative to the Ventum Ultralight K4 Pant, designed for active, multi-season use and with increased ease of layering under additional protection. The trim, tapered profile and ultralightweight fabric ensure easy mobility and layering, and wind-resistant protection wards off chilling gusts while retaining warmth generated from activity.

Built for Versatility

Ultralightweight, quick-drying fabric with 4-way stretch combines with articulated knees to provide versatile performance as both a layer and a standalone jogger. A dry clear coating offers a softer hand feel, and a hidden passport pocket and key clip add convenience to everyday use and adventuring alike.

The Avid Ultralight K4 Pant is crafted with bluesign®-certified textiles—verified for ecological safety at every step of manufacturing—and is certified STANDARD 100 by OEKO-TEX® as free from harmful levels of more than 100 substances.

Bulk-Free Profile

Low-profile construction with tapered cuffs and an elastic waistband delivers a trim fit, allowing comfortable layering beneath additional protection without bulk or bunching up. Combined with air-sealing softshell performance, the Avid is an ideal midlayer for extreme cold environments.

Air-Sealing Softshell

The wind-resistant softshell seals out chilling gusts while retaining warmth built up from active use, ideal for active use in cold to temperate weather or as a midlayer in extreme cold environments. A durable water-repellent (DWR) finish helps light precipitation bead up and roll off.


Technical Features

  • Ultralightweight
  • Wind resistant
  • Water resistant
  • 4-way stretch
  • Highly compressible
  • Fast drying

Fit & Design Details

  • Elastic drawcord waistband delivers snug, adjustable fit ideal for standalone or layered use
  • Tapered cuffs reduce layering bulk, help seal in heat from active use, and ensure visibility of feet during adventures
  • Articulated knees
  • Hidden zippered fly

Fabric Treatment

  • DWR (Durable Water Repellent) finish repels moisture
  • Clear coating on the outer shell increases the soft hand feel

Pocket Details

  • Two hand pockets
  • Two zippered rear pockets
  • Internal zippered passport pocket in right hand pocket
  • Key clip in left hand pocket


  • 86% nylon/14% spandex shell combines ultralightweight with 4-way stretch for exceptional mobility
  • Weight (Size L): 12.77 oz
  • Imported | TAA Compliant


  • Insulation is crafted from 100% post-consumer recycled content and is completely biodegradable
  • Certified STANDARD 100 by OEKO-TEX® | confirmed free from harmful levels of more than 100 substances
  • bluesign®-certified textiles have been verified for ecological safety at every step of manufacturing

Trade Agreements Act Compliant
Designed in Seattle. Imported.

Customer Reviews

Based on 17 reviews
Wes Senechal
Best lightweight pants on the market

The K4 pants is the perfect weight. It works well in cool weather and warm weather. It is great for early morning workouts and for casual use during the day. It pairs well with a t-shirt and flip flops and is like a “utility-knife” in my pack. I highly recommend these pants for any adventure. The fit is amazing and I love the cuff at the bottom of the legs. It is just the right size and looks clean.

Very comfortable all-use pant

Got the first pair in, ordered a second pair days later, grey and black. Didn’t have expectations when I initially ordered them, was just going to try them out but they are very comfortable. The pockets are functional, waistband is wide and soft, material seems abrasion resistant, overall great “joggers” in both cool and warm environments. Have worn them to the office, on weekends, and ran in them. Great all around. I have a 33” waist (actual measurement) and prefer the small for a cleaner/slimmer fit. Would recommend to anyone.

JP Fonder
Fantastic Pants

These pants are great. The back pockets are zippered which is great when riding my bike around to keep my wallet from falling out. The right front pocket has an inner pocket which fits my phone perfectly and it also zips closed to keep my phone from falling out. This pocket also keeps my phone from "sloshing" around in the bigger pocket while I walk, jog or hike. The fit is great. I am 6'2 200lbs and the medium long is perfect...not to tight but not baggy at all. They don't ride up or fall down. They are comfortable in weather from 55 to 85. Definitely recommend. My only thought for improvement would be a breathable liner similar to other active wear which don't require underwear. Wearing cotton underwear under these detracts from the perfection that is these pants.

Chris Beattie
Great Pants

I love this pants. I originally ordered the green and liked them so much I ordered another pair in gray. They fit good and have lots of pockets and features.

Ben Brooks
Comfortable and versatile

Wasn’t sure what to expect but these pants are great for lounging in, hiking, or yard work. Really great weight even as it gets warmer out, but also an excellent wind break too.

Need Help? Contact us with any size or fit questions. 206-767-0307

Men's Avid Ultralight K4 PantSizing Information

Height 5' 8" - 6' 2"

Short: -2 Inches Inseam

Long: +2 Inches Inseam

SizeWaistHipInseam Regular
Measurements in Inches

Waist Preferred Pant Waist

Hip 7" Below Preferred Waist

Inseam Regular Crotch to floor

silhouette diagram

Fit Information

Standard True to Size | Active Layering

silhouette diagram
Product is Standard Fit, developed to accommodate up to two layers, for cross-environmental versatility

Expedition Oversized | Static Layering

silhouette diagram
Product is Expedition Fit, developed to accommodate up to four layers, for extensive use in extreme weather

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