Trunk Size Chart

Fit Profile: True to Size

Size: S M L XL XXL
Waist: 28-30" 31-34" 35-39" 40-43" 43-46"
Outseam: 6-7" 7-8" 8-10" 10-11" 11.5"

  *Standard Trunk Size Guide Measurements:

Waist: Circumference measurement of waist. Trunks are designed to fit above the hips.

OutseamMeasure the length from the intersection of the waistband & hip to the bottom hem, follow the outer seam.

*Product measurements can vary by 1/2" 

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.

 

Flex Trunk

139 reviews

Flex Trunk

139 reviews

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

Color
Maroon Red
Black
Gray
Green
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Size Guide

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Flex Trunk ">
Description
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Flex Trunk ">

The Flex Trunks were designed for your more intense days. This custom blend has increased compression, breathability and support. It also features cooling mesh zones for anti-odor and temperature control.

The Flex Trunk
Polyester 84% POLYESTER
Spandex 16% SPANDEX
Flex Trunk
Breathable BREATHABLE
Anti-Odor ANTI-ODOR
The BYLT Difference
Style, performance & comfort are our design principles that we use in creating our entire line.
Our Guarantee
It is critical to us that you are happy with your purchase and that you love the items you receive. We know things happen, if you are not 100% satisfied, we will try our hardest to make it right.
Experience Premium
We're here to upgrade your basics. Every BYLT product is rigorously tested before it's shown to the world to ensure it is nothing less than premium.
Customer Reviews
4.8 Based on 139 reviews
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04/11/2017

Flex Boxer Briefs Live up to Hype

Dale H.

Excellent compression fit on legs but because I'm on the line for size I'd order up one size next time. Additional colors would be great!

02/28/2020

TRULY COMFORTABLE AND GREAT QUALITY!

Evan J.

I'm absolutely in love with how comfortable these are, the fit is perfect, the feel is perfect, the price is not so perfect....That's a lot of money to drop on underwear...I would like to purchase 5 or 6 more pair to replace my current underwear but thats a chunk of change.

02/22/2020

Very comfortable

Ryan

These underwear are extremely comfortable and fit great to your body. Definitely worth the price.

02/02/2020

All Day vs Flex

dave d.

Received a pair of all day version and when I ordered additional pairs did not realize there was a difference between flexible in all day. Much prefer the all day.

01/20/2020

Amazing Underwear

DN

These are most definitely the best pair of underwear I've ever worn.

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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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Trunk Size Chart

Fit Profile: True to Size

Size: S M L XL XXL
Waist: 28-30" 31-34" 35-39" 40-43" 43-46"
Outseam: 6-7" 7-8" 8-10" 10-11" 11.5"

  *Standard Trunk Size Guide Measurements:

Waist: Circumference measurement of waist. Trunks are designed to fit above the hips.

OutseamMeasure the length from the intersection of the waistband & hip to the bottom hem, follow the outer seam.

*Product measurements can vary by 1/2" 

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.