Mack Weldon Airknitx Boxer Brief vs Smartwool Active Merino
Buy the Mack Weldon Airknitx for hot weather, workouts and everyday wear at about half the price. Buy the Smartwool Active Merino for cold-weather outdoor days and multi-day trips where odor control matters most. As of November 3, 2026, the Airknitx is $21.99 and the Smartwool's best new price is $40.00 at Amazon. The Smartwool has dipped to $35.00 since November 1, so a price alert is worth setting.
Ask our shopping agent
Mack Weldon Airknitx Boxer Brief
Choose the Airknitx if you want the lightest, most breathable option and the lower price for gym days and warm climates.
Pros
- Very light and breathable with targeted cool zones
- Four-way stretch keeps legs in place all day
- Machine wash and tumble dry low
- About half the price of the Smartwool
Cons
- Synthetic fabric holds odor faster than wool
- Flyless pouch is not for everyone
- Thin fabric may feel too light in cold weather
What separates them
| Mack Weldon Airknitx Boxer Brief | Smartwool Active Merino | |
|---|---|---|
| Price | $21.99 | $40.00 at Amazon as of November 3, 2026 |
| Main fabric | Synthetic blend: 56% polyamide, 31% polyester, 13% elastane | 56% merino wool with polyester |
| Best climate | Hot weather and sweaty workouts | Cold to cool weather and changing temperatures |
| Odor control | Odor-fighting finish on synthetics | Wool resists odor naturally over multiple wears |
| Fit | True to size, four-way stretch, stay-put legs | Slim fit that follows the body |
| Chafing | No-roll waistband and smooth seams | Flatlock seams built to minimize chafing |
| Fly | Flyless pouch | No fly |
| Care | Machine wash cold, tumble dry low | Wool needs gentler washing and air drying |
Price history
$40.00$21.99
- Mack Weldon Airknitx Boxer Brief: lowest $21.99 on Nov 1 at eBay; $21.99 on Nov 2.
- Smartwool Active Merino: lowest $35.00 on Nov 2 at Moss Mountain Outfitters; $40.00 on Nov 3.
Prices at every store
Mack Weldon Airknitx Boxer Brief
- eBayCheck price at eBay
- Mack WeldonCheck price at Mack Weldon
- NordstromCheck price at Nordstrom
Smartwool Active Merino
- SmartwoolNew
In stock
$40.00Free shippingObserved at 2:56 AM - Zappos.comNew
In stock
$50.00Free shippingObserved at 3:34 AM - REINew
In stock
$50.00+ $7.99 shippingObserved at 3:34 AM - AmazonNew
Availability unknown
$40.00Free shippingObserved at 2:56 AM
Also available at
- ModeSensCheck price at ModeSens
- Moss Mountain OutfittersCheck price at Moss Mountain Outfitters
- PoshmarkCheck price at Poshmark
Specs compared
| Spec | Mack Weldon Airknitx Boxer Brief | Smartwool Active Merino |
|---|---|---|
| Fit | Designed to be true to size | Slim fit |
| Fabric composition | 56% Polyamide / 31% Polyester / 13% Elastane | — |
| Hem style | Shirttail hem | — |
| Stretch | Four-way stretch | — |
| Care | Machine wash cold with like colors. | — |
| Drying | Tumble dry low. | — |
| Origin | Imported | — |
| Material composition | — | 56% Merino Wool |
| Seam construction | — | Flatlock seam construction |
| Waistband | — | Wide elastic waistband |
| Front panel |
Questions and answers
- Which is better for hot weather and workouts?
- The Mack Weldon Airknitx. Its synthetic knit is built for airflow and moisture wicking, and it dries fast. Merino is better at odor control but warmer and slower to dry.
- Which lasts longer?
- Both hold up well. Merino wool keeps its shape and odor resistance over many wears, while the Airknitx relies on elastane stretch that can loosen over years of washing and drying.
- Is the Smartwool worth double the price?
- Only if you need wool's temperature regulation and odor resistance, such as cold-weather hiking or several days between washes. For everyday wear and gym use, the Airknitx does the job for less.
- Do either have a fly?
- No. The Airknitx uses a flyless pouch, and Smartwool buyers note the Active Merino has no fly.
- Which is better for multi-day trips?
- The Smartwool. Wool resists odor across multiple wears, so you can pack fewer pairs. The Airknitx is lighter and cooler but needs washing sooner.
- How do the fits compare?
- The Airknitx is designed true to size with four-way stretch and stay-put legs. The Smartwool is a slim fit that follows the body, so size up if you prefer room.