A lighter and stronger take on underwear, we created this fabric with plenty of nylon for strength, modal for softness, spandex for stretch, and silver for odor resistance. The knit structure of the fabric is open and breathable, and works very differently than our Merino Wool Underwear. Instead of pulling moisture into the core, it wicks it away. While the anti odor performance will not be as effective as our merino products, it dries faster and can be washed and ready to wear within a few hours. This product does not feature the SmartGrip System found in our Merino Wool underwear; otherwise, the construction and components are identical.


SilverAir Ultralight Boxer Brief
Carbon Black
Carbon Black
Carbon Black
Carbon Black
Stone Grey
Stone Grey
Stone Grey
Stone Grey
Polar White
Polar White
Polar White
Polar White

Boxer Brief Flyless

43 Reviews

$ 24.00 $ 28.00

  • Polar White
  • Stone Grey
  • Carbon Black
  • S
  • M
  • L
  • XL
  • XXL
    • Lightweight open-knit fabric dries quickly
    • SilverAir Technology reduces odor
    • Double soft waistband doesn't roll over or leave marks
    • 50% Nylon, 35% Modal, 10% Spandex, 5% Metallic
    • Manufactured in China


(based on body measurement in inches)


If you don't love your first pair, you can return it within 30 days of purchase for a full refund or a different size.

Customer Reviews

4.8 Based on 43 Reviews
5 ★
4 ★
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Joseph H.
United States

Great workout/everyday underwear

I've owned a number of premium underwear brands, including Y's own SilverAir Merino variety. The fit of these is pretty much the same, which is to say it's very good. Enough support for workouts and HIIT, but not too much so that it's still very comfortable to wear as a daily driver. In fact, they are one of the most comfy boxer briefs I've ever worn. Compared to the merino underwear, these are a lot lighter and airier. The merinos are great to wear as travel underwear, as well as for gym days. These new ones would be equally good for gym days, but I'd feel a lot better about running in them since they're so much lighter. I can't attest to the durability of these yet since they're brand new, but because they are so thin and light, I hope they hold up as well as some of my other premium activewear. We'll see! Otherwise, highly recommended.

A Y Athletics Customer
Padraic R.
United States United States

Good, but do we really need a horizontal fly?

Good fit, great odor resistance, but did we need to reinvent the fly orientation? Was there something wrong with the vertical fly on every other undergarment ever made? I am still getting used to horizontal, every time wondering why the retraining is worth the time

Jim Z.
United States United States

Great Product Super Comfortable!

The original is still fantastic, however these ultra light weight briefs are amazingly comfortable even on a 23 hour travel schedule!

Timothy P.
United States United States

Great items, just limited stock

Would be a 5 star, but unfortunately I am usually on my second or third choice of items or colors everytime I order. XL OR XXL is usually sold out, and want plain black socks?! Sometimes they pop up...but you most likely will need to get gray. Want the ultralight underwesr in XXL with a fly? Nope....gotta get the flyless. PLEASE stock more sizes and items in human sizes!! Not sure how often you miss sales, but I have had people I suggested you too say, yeah, I looked, nothing I wanted/needed in my size/color. Premium pricing, premium product, unfortunately discount store selection.

Tim M.
United Kingdom United Kingdom

10/10 customer service

Me: I want to order a bunch of stuff including xyz socks you are sold out according to your website. When will you get them in? You: I just checked the storeroom and I have 6 pairs. Do you want them? Me: awesome. Thanks so much !!