308 Smoothing At Waist Brief
Navy
$19.99
- 3 FOR $49
NEED TO RETURN FOR A REFUND OR EXCHANGE?
No Problem - We're Happy to Help!
180 DAYS. NO RUSH...
If something isn't quite right with your purchase, don't worry! We offer free returns or exchanges within 180 days, no questions asked.
TRY IT ON. WASH IT. TRY AGAIN.
We want you to feel comfortable and confident in your new UNDEROUTFIT, so go ahead and wear it and wash it as much as you like. If the fit still isn't right, don't worry - we offer free exchanges and returns.
IT'S NOT AS SMALL AS IT LOOKS
When you first receive your purchase, it may appear too small, but give it a try anyway. You'll be pleasantly surprised to find that it's the correct size. This is due to the unique yarn technology we use.
BONUS: We offer free exchanges for all U.S. customers, even if the product has been worn and washed. So, try it on!
Please keep in mind that the original shipping charge (for orders less than $70) is non-refundable.
START RETURN / EXCHANGE
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Note: Free items cannot be refunded, but you may exchange them or skip to the next item.
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Although taxes won't be shown, they will still be refunded.
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Please note the original shipping charge (orders less than $70) is non-refundable.
180 Days To Try At Home
We have a 180-day return policy, which means you have 180 days after receiving your item to request a return.
Please note the original shipping charge (orders less than $70) is non-refundable.
Try It!
We encourage people to try it at home. Put it on. Don't worry, we will accept it back. If you don’t love your first item, we'll send you a different size or style or issue you a full refund.
Try Few Sizes
We understand that sometimes you may need to order two or more sizes to find your perfect fit, even in our shapewear/underwear.
We encourage you to try at home. We ask that you only open up the plastic polybag on the shapewear/underwear you have chosen to keep. Once the shapewear/underwear is removed from the package, it is considered worn, and it cant be restocked, but we will exchange it or refund it without restocking it.
Lingerie
Expertise
Why Underoutfit
Smoothing that disappears under everything
Our founders spent 30+ years designing for Victoria’s Secret, Nike, Spanx, Lululemon, Triumph, Maidenform and more. They built the 308 Brief to solve what no other underwear had — a waistband that smooths without digging, shapes without compressing, and disappears under any outfit.
Engineered to smooth and contour at the waist without any pressure, rolling, or digging into the skin — even after a full day of wear.
Ultra-thin seamless construction lies completely flat under fitted dresses, trousers, and activewear — invisible from every angle.
Soft, breathable fabric moves with your body from morning to night. Not shapewear — just underwear that happens to smooth beautifully.
Wear it, wash it, try it again. Return or exchange free for 180 days — we pay the shipping both ways.
Engineered for Comfort
Every Detail, Designed with Intention
Three decades of intimate apparel expertise went into every stitch. Here’s what makes the 308 Smoothing Brief different from anything you’ve worn before.
Smoothing Waistband — No Digging
Our proprietary waistband is engineered to smooth and contour at the waist with the perfect balance of compression and comfort. No rolling, no digging, no red marks at the end of the day — just a clean, contoured silhouette from morning to night.
Seamless Under Any Outfit
Ultra-thin seamless construction means the 308 Brief lies completely flat under fitted dresses, trousers, skirts, and activewear. No visible lines, no bunching, no adjusting. Wear it under anything and forget it’s there.
Shaping That Feels Like Nothing
Soft, breathable fabric moves with your body all day long. The 308 Brief is not shapewear — it’s everyday underwear that happens to smooth beautifully. Light enough to forget, effective enough to transform how your clothes fit.
Customer Reviews
2,836 Women Can’t Be Wrong
“I’ve been searching for underwear that smooths without squeezing for years. This is it. The waistband sits perfectly, no rolling, no digging. I wear them every day and I’ve ordered six more pairs in different colors.”
“These are the most comfortable underwear I’ve ever owned. They’re not shapewear — they just make everything look smoother. I wore them under a fitted dress to a wedding and got so many compliments on how I looked.”
“I bought these with the matching bra and it’s the best set I’ve ever owned. The brief smooths my waist beautifully and I forget I’m wearing them. The 180-day guarantee meant I had nothing to lose trying them. Now I’m a customer for life.”
Join over 1 million women who have already made the switch.
Shop the 308 Smoothing BriefOur Story
Designed by the people who built the industry
Our founders spent 30+ years designing bras for Victoria’s Secret, Nike, Spanx, Lululemon, Triumph, Maidenform and more. They know what works — and they know what women actually want. Now they’re bringing that expertise directly to you.
Expert Craftsmanship
Every bra is the result of decades of intimate apparel engineering. Perfected fit for millions of women worldwide.
Women-First Design
Every detail is made for real bodies and real life. We design for how women actually live — not how they’re supposed to.
Trusted by 2M+ Women
Over one million customers have made Underoutfit their everyday essential. Join a community that knows what comfort really means.
“A bra to forget. — that’s not a tagline. It’s the standard we hold ourselves to every single day.”
Our Promise to You
180 Days to Fall in Love
We’re so confident you’ll love our garments that we give you 180 days to decide. Wear it, wash it, try it again. If it’s not right, return or exchange it — completely free.
- 1 Order your size — or try two sizes at once
- 2 Wear it, wash it, wear it again
- 3 Not right? Return or exchange — free, for 180 days
Wash & Wear · Free Returns · Free Exchanges






