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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? Book a virutal fitting with our amazing customer experience team!
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68 Points
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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
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Molded cups for lift & support
Mesh detailing at bust to prevent spillage
Back mesh panels for a smooth silhouette
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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: 240 Total 4 star reviews: 71 Total 3 star reviews: 53 Total 2 star reviews: 54 Total 1 star reviews: 50
What our customers are saying
Generated by AI from 100 most recent customer reviews
Last updated 3 days 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.
68%would recommend this product
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Current Cup Size
Purchased Knix Size - Number Sizing
468 reviews
- Rated 2 out of 5 stars1 hour agoStrange fit
Purchased two in my usual size that I would purchase from any other brand... I can only do up the last clasp on this one. Throughout the day I felt like I was constantly readjusting... and the underwire squeaked with every move. Decided to return one and keep one to see how things go with wear over time. I would recommend sizing up in band if you're going to give this one a try.
Kirstin K.Verified ReviewerReviewingFreeFlex™ Demi Bra - Rated 1 out of 5 stars1 week agoDisappointed
Love the brand but last time I’ll be purchasing.
I used their size guide and question it because didn’t seem like my usual side. I triple checked and in the end followed their size recommendation. Should have trusted my gut it was too small and final sale 🙄. Why bother having a size guide.
DeniseVerified BuyerReviewingFreeFlex™ Demi Bra - Rated 2 out of 5 stars1 week agoVery off-size
Very disappointed with this bra. I carefully followed the size guide to select the appropriate size. However, the actual fit does not align with the sizing information provided. Both the band and cup size are too large. The top part of the band feels noticeably looser than the bottom, which creates an uneven and unsupported fit. The cups are much too loose—fitting like the C-cup bras I already own, rather than a B cup. And the underwires feel uneven and not at all smooth as described. I use to be a big fan of Knix, but this one is a big dissapointment. The bra was on sale so I can't exchange it.
AudreyVerified ReviewerReviewingFreeFlex™ Demi Bra - Rated 5 out of 5 stars1 week agoAwesome bra
I’ve been searching and trying so many different bras, came across this one and it’s a keeper! I absolute love how it fits? Doesn’t gape or cause overflow! 10/10
Sandy G.Verified BuyerReviewingFreeFlex™ Demi Bra - Rated 5 out of 5 stars1 week agoBra purchased
Love the bra. I will buy a couple more when I come to town. The service was beyond excellent.
Karen
Karen G.Verified BuyerReviewingFreeFlex™ Demi Bra - Rated 5 out of 5 stars1 week agoGreat bra
Comfie despite the wire support.
SARAH C.Verified BuyerReviewingFreeFlex™ Demi Bra - Rated 5 out of 5 stars3 weeks agoMy favourite bra
My favourite bra! Its so soft and the wire is the perfect support. The quality is amazing. I love knix bras but this one takes the crown!!
Jessica C.Verified BuyerReviewingFreeFlex™ Demi Bra - Rated 3 out of 5 stars3 weeks agoFree Flex Demi bra
Ordered my usual size and feel like the fit is not right. The cup size seems too large and the band is tight. My biggest complaint is the zigzag stitches are irritating to the skin. The bra seems to be poorly structured and the sides are bulky
Gaye S.Verified BuyerReviewingFreeFlex™ Demi Bra - Rated 5 out of 5 stars1 month agoGreat bra
I wasn’t sure about this bra because I usually enjoy something a little cuter looking. But I have to say I reach for this bra anytime I need something smoothing with great support. Will definitely buy another!
Henrietta B.Verified BuyerReviewingFreeFlex™ Demi Bra - Rated 4 out of 5 stars1 month agoEvening Wear
Purchased the FreeFlex Demi Bra to wear with my “more form fitting evening wear. I find it to be comfortable initially but after three or four hours, it is tightening and I find I am constantly “adjusting “ where the band sits and looking forward to taking it off.
Carol C.Verified BuyerReviewingFreeFlex™ Demi Bra - Rated 5 out of 5 stars1 month agoMy new fav bra!
Literally bought 3 of the Demi Flex bras in and considering buying a fourth in a new colour! Shipping is in a decent time frame!
Lydia J.Verified BuyerReviewingFreeFlex™ Demi Bra - Rated 5 out of 5 stars1 month agoGood
Unfortunately, I took small size, next time will be careful, but it is really good
Viktoriia Z.Verified BuyerReviewingFreeFlex™ Demi Bra
