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Flex Trunk Size Chart

Trunk

Fit Profile: True to Size
Flex Trunk Size Guide
Size: S M L XL XXL
Waist: 28-30" 31-34" 35-39" 40-45" N/A
Leg: 6-7" 7-8" 7-8" 8-10" N/A

 

Your purchase includes our "Love Your Fit" guarantee

If you don't love the fit, send it back and we'll exchange the size so you're happy.

 

Sale

Flex Trunk

93

Designed with increased compression, breathability, and support for your more intense days. Learn More

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Size Guide

Flex Trunk

Signature 40° Side-Fly • Anti-Odor • Temperature Control • 84% Polyester  16% Spandex


“Lightweight, comfortable, and durable. I can wear the Flex Trunk anywhere with confidence that they will perform!" 




  • You deserve better boxers


      • Cool Where it Counts

    84% Polyester and 16% Spandex, our mesh zones are strategically placed to remove heat and keep you cool when and where it matters most.

      • Side Fly Innovation

    BYLT's signature 40º side-fly offers a more comfortable draw and easier access. It's time you see how we changed men's boxers for the better.

      • No Roll. No Marks.

    The Flex Trunk's no-roll waistband fits comfortably while leaving you mark free after a long day. Say goodbye to boxers that roll and ride up.




    Men's Temperature Control Flex Trunk Underwear Pack by BYLT Basics.



 

Customer Reviews

Based on 93 reviews
5 Star
80% 
74
4 Star
17% 
16
3 Star
2% 
2
2 Star
0% 
0
1 Star
1% 
1
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03/09/2019

Best Briefs I’ve ever owned

MVLO

Im switching all my undwrwear over to the flex boxer brief. They are absolutely amazing

03/09/2019

Best money ever spent

Jason L.

The most comfortable pair of underwear I’ve ever owned.

03/08/2019

Comfort

Paul

Overall one of the best pair of underwear that I purchased. I bought the value pack after I tried these on for the first time. Good Fit and Feel. I walk a sit a lot, and I usually feel uncomfortable through out the day. With these pairs I feel dry and the material feels good on my skin. One thing I love is the front pocket. I see in the other reviews that everyone raves on this. I hate to sound bad but its easy access and do not know why others have not thought about it. Overall I would recommend. Just heads up that these trunks fit a little longer than standard trunks that I am use too. I use to use Hugo Boss and Express, and when I compared the size the BYLT was longer and almost felt like boxer briefs but that is a small point and well worth the purchase. The material still feels great after I washed them and so the quality does not go away and also there is no stretch of the material after you wear them. I have a little belly (working on getting smaller) and usually the other brands I use tend to stretch out. Overall highly recommend!!!

03/04/2019

Best Trunks Ever

Munir P.

The only reason I’m upset is that now I have to buy more! Great feel, great to workout in, and my fiancé loves the look!

03/04/2019

Get them

Nathan S.

The front pocket is awesome. Not sure why any other underwear would be designed different.

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Our Signature Fabrics

BYLT Blend™ Fabric

Premium signature blend of Cotton, Polyester, and Spandex. Perfect for your essential everyday shirt leaving you with that flawless BYLT Fit.

LUX Blend™ Fabric

High-quality performance blend of Cotton, Polyester, and Spandex. Reactive fabric allows for slight reduction in length to provide the perfect structured fit.

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Flex Trunk Size Chart

Trunk

Fit Profile: True to Size
Flex Trunk Size Guide
Size: S M L XL XXL
Waist: 28-30" 31-34" 35-39" 40-45" N/A
Leg: 6-7" 7-8" 7-8" 8-10" N/A

 

Your purchase includes our "Love Your Fit" guarantee

If you don't love the fit, send it back and we'll exchange the size so you're happy.