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ACOTAR™ Leakproof Ultrathin No-Show Bikini Box Set
ACOTAR™ x Knix
ACOTAR™ Leakproof Ultrathin No-Show Bikini Box Set
$125.00
CAD
Coming Soon • Oct 15
Limited-edition ACOTAR™ x Knix collection
Absorbs about 2.5 super tampons
Invisible under clothes
Moderate protection without the bulk
Machine washable
Size and Fit Guide
How to Measure
In order to select the correct sizing, we recommend you take the following measurements using a soft tape measure. If necessary, ask someone else to help.
Waist
Measure around the narrowest part of your torso, usually just above your belly button. Keep the tape snug and level, but not tight. The number where it meets is your waist measurement.
Hip
Stand with your feet together and measure around the fullest part of your hips and buttocks. Keep the tape level and snug, but not tight. The number where it meets is your hip measurement.
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Part of the limited-edition ACOTAR™ x Knix Collection
Comfort-First Fit
Bikini silhouette with a classic mid-rise fit, medium hip and bum coverage.
Moderate Absorbency
Absorbs 2.5 super tampons worth of liquid—perfect for moderate flow days, light bladder leaks, and sweat. The carbon cotton gusset top layer keeps you dry.
Worry-Free Protection
Perfect for moderate period days, light bladder leaks, and sweat. Moisture-wicking liner keeps you dry and comfortable.
No-Show Style
Buttery-soft and smooth fabric gives a seamless look and feel. Disappears under clothes, even leggings.
Easy to Wash
Machine washable, just like your regular underwear.
ACOTAR™ is a trademark of Fireheart Inc. ©2015-2026, Sarah J. Maas.
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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
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Reviews Summary
Generated by AI from 100 most recent customer reviews
Last updated 4 months ago
Customers say these period underwear are comfortable and provide effective protection without the bulk of traditional pads. Many appreciate the soft, buttery fabric that feels like regular underwear and the no-show design under clothing. Users frequently mention confidence during workouts, daily activities, and even swimming. Parents often purchase these for teenage daughters who love the comfort and security they provide. Common feedback includes praise for the absorbency and leak-proof performance. However, several reviews mention sizing inconsistencies, with some finding recent purchases run smaller than previous orders. A few customers note the leg holes can feel tight or that the fit varies between different fabric types.
84%would recommend these products
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742 reviews
- Rated 5 out of 5 starsYesterday5 Stars
Tissus agréable et mince
FFranceReviewingLeakproof UltraThin No-Show Bikini 3-Pack Eucalyptus/Rose Quartz/Rosewood / XL - Rated 5 out of 5 stars1 week agoSecond skin
I love these underwear! They're smooth and sleek. No pantylines.
MFMalinda F.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini 3-Pack - Rated 5 out of 5 stars1 week agoLove. Totally switched over to Knox now.
Love love love these. I’m officially switched over now to Knix underwear.
NRNikki R.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini 3-Pack Mulberry/Pink Party/Wild Iris / L - Rated 5 out of 5 stars1 week agoAmazing
Absolutely love these underwear. They are true to size and I bairly notice they are there. Highly recommend.
CSCecily S.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini - Last Call Indigo / M - Rated 5 out of 5 stars1 week agoIndispensable
Flattering fit and reliable protection. Which is saying a lot — even bloated and on my period these undies hold a good silhouette. Nothing like confidence to get you through an otherwise exhausting few days.
CWcynthia w.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini - Rated 5 out of 5 stars1 week agoRecent bikini purchase
They run a little small for medium, but overall, really pleased with them.
WCWendy C.Verified BuyerReviewingPOS - Leakproof UltraThin No-Show Bikini (ZSkus) Black with White Polka Dot / M - Rated 5 out of 5 stars2 weeks agoTeen Leakproof Bikinis
I bought these for my teenage granddaughter and she loves them. So comfortable and are perfect for light days.
DDDebbie D.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini 3-Pack Eucalyptus/Rose Quartz/Rosewood / M - Rated 5 out of 5 stars2 weeks ago5 Stars
best underwear ever!!!!
RReneeReviewingLeakproof UltraThin No-Show Bikini Kit* Black with White Polka Dot / L - Rated 5 out of 5 stars2 weeks ago5 Stars
absolutely fantastic!!!! Fits well. I want more
RReneeReviewingLeakproof UltraThin No-Show Bikini Kit* - Rated 5 out of 5 stars2 weeks agoExcellent fit
Overall protection and fit as stated
BLBerenice L. L.Verified BuyerReviewingPOS - Leakproof UltraThin No-Show Bikini 3-Pack - Last Call - Rated 5 out of 5 stars2 weeks agoPerfect fit
I'm 5'11 170 and ordered the medium size. The fit is perfect not tight around the legs and the sweat protection is great.
BLBerenice L. L.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini - Rated 5 out of 5 stars2 weeks agoComfy and no show
Comfy no show and effective
CBCindy B.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini Black / S
