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Why You'll Love This
No seams, no lines, no distractions. A smooth waistband and four way stretch go anywhere.
VANGUARD
Say goodbye to waistband digs, underwear lines, and the friction distractions of your final mile ride.
SILVADUR™
SILVADUR™ antimicrobial delivers "intelligent" microbial control of bacteria that cause odor.
PRIME WICKING
AEROSKYN™'s 3D fiber network channels sweat and accelerates evaporation at core temperature.
MAXI-AIRFLOW
Airburst™ technology keeps you dry and cool, delivering the ultimate gear that eliminates discomfort.
Product Details
Designed for Peak Performance
Designed for Peak Performance
Product Features
Product Features
Size & Fit Suggestions
Size & Fit Suggestions
Activities
Activities
Material & Care
Material & Care
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Machine Wash Cold
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Hang Dry
Best Pair Guarantee
- WYWilliam Y.Verified BuyerReviewingPREVAIL · CLASSIC BRIEF XXLI recommend this productRated 4 out of 5 stars9/30/25My everyday comfort pick
Honestly, they work in every setting—work, gym, or just hanging out. Light, breathable, and easy to wash.
- MPMateus P.Verified BuyerReviewingPREVAIL · CLASSIC BRIEF SI recommend this productRated 4 out of 5 stars9/30/25Great for Long Rides
I wore these on a full weekend bike trip and they stayed fresh and comfortable the whole time. If they go on sale, I'll definitely be buying several more pairs.
- LTLuca T.Verified BuyerReviewingPREVAIL · CLASSIC BRIEF SI recommend this productRated 4 out of 5 stars9/19/25Nice for Pilates
Flexible and soft during Pilates – no pinching or discomfort even in deep stretches.
UUnderXLabs9/21/25Hi Luca T., we're delighted they provided flexible comfort during Pilates without pinching in deep stretches! Perfect for your practice.
- EOEthan O.Verified BuyerReviewingPREVAIL · CLASSIC BRIEF LI recommend this productRated 4 out of 5 stars8/25/25Cycling Base
Perfect under cycling tights, no seams to cause irritation.
- ITIvan T.Verified BuyerReviewingPREVAIL · CLASSIC BRIEF SI recommend this productRated 4 out of 5 stars8/19/25Seam-Free Bliss
Smooth comfort with no seams noticeable even under tight jeans.
UUnderXLabs8/21/25Hi Ivan T., we're thrilled they provide smooth comfort with no noticeable seams even under tight jeans! That discreet wear is perfect.
- FDFelipe D.Verified BuyerReviewingPREVAIL · CLASSIC BRIEF MI recommend this productRated 5 out of 5 stars7/20/25So soft
Excellent support and breathability perfect for daily wear.
UUnderXLabs7/21/25Hi Felipe! So glad they're working perfectly for daily wear! That breathable support is what we're all about. Enjoy!
- VUVictor U.Verified BuyerReviewingPREVAIL · CLASSIC BRIEF MI recommend this productRated 4 out of 5 stars7/19/25Workout Approved
Remains in place during workouts and keeps me reasonably cool.
UUnderXLabs7/21/25Hi Victor U., we're delighted they remain in place during workouts while keeping you reasonably cool! That reliable performance is key.
- WDWei D.Verified BuyerReviewingPREVAIL · CLASSIC BRIEF LI recommend this productRated 4 out of 5 stars7/18/25Held up on a road trip
Stayed comfortable on a long car ride without sticking or bunching.
UUnderXLabs7/20/25Hi Wei D., we're glad they stayed comfortable without sticking or bunching during your long car ride! That consistent comfort is exactly what we design for.
- FDFelipe D.Verified BuyerReviewingPREVAIL · CLASSIC BRIEF XLI recommend this productRated 5 out of 5 stars7/10/25My whole family switched
12-hour coding sessions in these feel like wearing pajamas, but they look professional enough for surprise Zoom calls. The waistband doesn't constrict when I'm slouched in my ergonomic chair for hours. Keyboard warrior approved no wedgies during crunch time, and the breathability prevents that weird gamer sweat situation. My standing desk marathons just got 23% more comfortable.
- SWScott W.Verified BuyerReviewingPREVAIL · CLASSIC BRIEF XXLI recommend this productRated 5 out of 5 stars7/10/25Golf approved
After years of searching, I can confidently say these are the best underwear available. Every detail is engineered for maximum comfort and performance.
UUnderXLabs7/19/25Hi Scott! Thanks so much for the fantastic 5-star review! We're absolutely thrilled to hear that the Prevail has finally ended your years-long search for the perfect underwear - that's exactly what we hoped to achieve! It's wonderful that you're experiencing how every detail has been thoughtfully engineered for maximum comfort and performance. We put a lot of effort into perfecting each element, from the seamless construction to the moisture-wicking fabric, to create underwear that truly performs when it matters most. Golf-approved comfort is high praise - we know how important it is to have underwear that moves with your swing and keeps you comfortable through all 18 holes! We really appreciate you taking the time to share your experience!