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FreeFlex™ Demi Bra
FreeFlex™ Demi Bra
$68.00
USD
2 for $90
Our first underwire bra
Comfortable, flexible wire
Lifts and separates
Lightly lined molded cups
Size and Fit Guide
Use Our Calculator to Find Your Traditional Bra Size
Step 12 of 2
Your Results
Measure Your Under Bust
Measure Your Full Bust
Wearing an unpadded bra, wrap a measuring tape around the top of your ribcage. You’re looking for a snug fit - so we recommend tightening on the exhale and noting the smallest measurement to the decimal.
Wrap the measuring tape around the fullest part of your chest, making sure the measuring tape is paralell to the floor. Relax your shoulders and measure where it falls.
At Knix, your size is
Still have questions? Ask our virtual assistant about finding the perfect fit.
Still have questions? Reach out to info@knix.com to learn more about our sizing.
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Product Description
The Underwire Bra Reinvented
Wear tested for over 625 hours, providing unparalleled lift, separation, and support.
All Day Comfort
It's everything you want from an underwire bra without the downfalls of one.
Feels Made For You
Lightly lined, molded demi cups lift and separate for a great shape that looks amazing under lower necklines and T-shirts. Adjustable straps create the perfect fit.
Smooth Coverage
The ultimate t-shirt bra that appears invisible under clothes.
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How to Choose?
Essential
- • Days you don’t need leak protection. Everyday freshness and moisture wicking.
-
0 tsp
Heavy
- • Extra peace of mind. For the first days of your cycle, light bladder leaks, or a full night's sleep without a leak.
-
about 8-14 tsp
-
about 1.5-3 regular pads
-
about 4-7 super tampons
-
about 1.5-3 menstrual cups
Light
- • Daily freshness. For sweat, discharge, period spotting, or backup protection.
-
about 1-3 tsp
-
about 1-3 pantyliners
-
about 1-3 regular tampons
-
about 0.5 menstrual cups
Moderate
- • For mid-cycle flow, surprise cough or sneeze leaks, or a really sweaty spin class.
-
about 4-8 tsp
-
about 1-1.5 regular pads
-
about 2-4 super tampons
-
about 0.5-3 menstrual cups
Ultra
- • Ultimate peace of mind. For the heaviest period days, light bladder leaks, unexpected postpartum flow, or overnight protection.
-
about 15-20 tsp
-
about 1.5-2.5 super pads
-
about 7-11 super tampons
-
about 2-3 menstrual cups
How it Compares
Shape & Smooth Bra
Molded cups for lift & support
Mesh detailing at bust to prevent spillage
Back mesh panels for a smooth silhouette
WingWoman Contour Bra
Molded cups lightly lift & separate
Extra side coverage prevents spillage
Comfortable, wireless support
Revolution V-Neck Bra
Wireless, removable cups
Buttery-soft BeyondSmooth™️ fabric
Four-way stretch for total comfort
Uplift Push Up Bra
Embedded raised foam panel for natural lift
Molded cups define your shape
Comfortable, wireless support
FreeFlex™ Demi Bra
Comfortable, flexible underwire
Lightly lined cups
Lifts and separates
Revolution Shadow Mesh Bra
Wireless, removable cups
Buttery-soft BeyondSmooth™️ fabric
Mesh detail at bust prevents spillage
Revolution Scoop Bra
Wireless, rounded cups
Buttery-soft BeyondSmooth™️ fabric
Versatile scoop neckline
FREEFLEX™ TECHNOLOGY
Carbonized Flexible Wire
Rigorous Comfort Testing Wear
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Recently Viewed
Total 5 star reviews: 244 Total 4 star reviews: 73 Total 3 star reviews: 57 Total 2 star reviews: 57 Total 1 star reviews: 52
What our customers are saying
Generated by AI from 100 most recent customer reviews
Last updated 2 weeks ago
Customers say this underwire bra offers excellent comfort and support for many users, with several praising it as the most comfortable underwire bra they've owned. Many reviews mention the soft fabric and good lift it provides. However, common feedback includes a significant squeaking or creaking noise from the underwire that occurs with movement, which many find annoying and noticeable to others. Frequent comments address sizing inconsistencies, with some finding it runs small while others experience gapping or poor fit. Several users note discomfort at the center gore area between cups, and some mention strap adjustment issues. While many customers became repeat purchasers and highly recommend it, others found the noise and fit problems made it unwearable despite the comfort.
67%would recommend this product
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Purchased Knix Size - Number Sizing
483 reviews
- Rated 5 out of 5 stars3 minutes agoNice bra!
This bra is comfy, and unlike the Wingwoman (which I still love) it separates as well as supports. Game changer - I'm finally back to wearing underwire again after all these years!
Karen D.Verified BuyerReviewingFreeFlex™ Demi Bra - Rated 5 out of 5 starsYesterdayForever a Knix fan
I love this set so comfy and good material. I’m obsessed with my knix sets
alicia S.Verified BuyerReviewingFreeFlex™ Demi Bra - Rated 3 out of 5 starsYesterday3 Stars
These bras did not fit my large chest. I really wanted to love them though.
AlyseReviewingFreeFlex™ Demi Bra - Rated 3 out of 5 starsYesterday3 Stars
These bras did not fit my large chest. I tried multiple sizes. I really wanted to love them though.
AlyseReviewingFreeFlex™ Demi Bra - Rated 3 out of 5 stars2 days agoSqueaky
I always rely on reviews. I have a few knix bra styles and have found them to fit slightly larger than what I normally wear. This one is the exception to that rule. I initially ordered a size down (based on my experience) and had to return to get my true size. Knix was great and no issues. Except that this bra squeaks. The underwire in the centre as well as the sides play a symphony of squeaks. It’s definitely not a 12hr shift bra but I can manage 8hrs. It certainly lifts and supports.
Erin O.Verified BuyerReviewingFreeFlex™ Demi Bra - Rated 1 out of 5 stars2 days agoFree flex Demi bra
Size was correct. 36 a but after wearing it all day I couldn’t wait to take it off. The wires rubbed me inbetween my breast’s. The most uncomfortable bra Knix has ever made. Disappointed I ordered two. One was damaged. Should have gotten a refund. When I tried it on it felt great. But after a days wear I was in pain.
Richelle G.Verified BuyerReviewingFreeFlex™ Demi Bra - Rated 5 out of 5 stars4 days agoLove
This bra fits perfect , no gaps,
Comfortable, seamless
Give u a little cleavage
Looks smooth under
Clothes I am totally hooked on these bras
Pat Z.Verified BuyerReviewingFreeFlex™ Demi Bra - Rated 4 out of 5 stars4 days agoOverall good
Overall it’s good, the underwire squeaks though and there is some creasing in the cups that is not going away with washing. Definitely fits really tight for a while but loosens up a bit. I am between a c and d cup so the C I had some spillage and the D does gape a small bit. I am also very muscular in the chest so not much tissue at the top, this might have to do with it as well. Have had mine for about a month and it’s still quite snug but I have been assured it will continue to loosen up.
Stephanie S.Verified BuyerReviewingFreeFlex™ Demi Bra - Rated 2 out of 5 stars1 week agoDoesn’t work for me
The bra fit okay, but possibly a different size may have been better. Even though it had an underwire, the sides stuck out rather than being close to the body. It really isn’t a good bra for me.
Carol M.Verified BuyerReviewingFreeFlex™ Demi Bra - Rated 3 out of 5 stars1 week agoDemi Bra - "ok" but disappointed.
Not overlay thrilled for the money.
Wouldn't purchase again.
Gerie M.Verified BuyerReviewingFreeFlex™ Demi Bra - Rated 2 out of 5 stars1 week agoFits small, final sale
Fits sooooo small. I want to love it, but can’t wear it. I didn’t realize it was final sale upon purchasing unfortunately.
Rebecca C.Verified BuyerReviewingFreeFlex™ Demi Bra - Rated 2 out of 5 stars1 week agoDisappointing
I ordered two of these bras because they were on sale, but I can’t wear them and I can’t return them, as they were a final sale (which I knew before I bought them). I ordered the size that the size chart indicated, but the cups gaped at the front, the underwire poked me, and the band was too tight, making for an uncomfortable fit. The reason I gave two stars is because the dusty pink colour is absolutely invisible under white, which is great. But really, not a good buy at all.
Joanna G.Verified BuyerReviewingFreeFlex™ Demi Bra
