Triangle Bra | Sienna
wireless, Keyhole Cutout, Convertible strap, and Front Adjust Straps
- Regular price
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$68.00 - Regular price
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- Sale price
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$68.00
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Meet your go-to wireless bra for effortless comfort and style—our Triangle Bra in Sienna. This ultra-soft, supportive triangle bra was co-created with our community to offer a barely-there feel and all-day wearability. It features front-adjusting straps and an adjustable racerback hook so you can personalize your look. A subtle center keyhole adds breathability and just the right touch of everyday sexy.
Why our community loves it: The keyhole detail isn’t just cute—it’s functional. Wear-testers told us it helped reduce sweat and made the bra feel more breathable, especially in warmer weather. Bonus: it looks great peeking out from under low-cut tops.
Model Fit Notes: Elise wears size S+ in Sienna. She’s 5'10" with a 37" full bust and 32" underbust. Mary wears size M in Sienna. She’s 5'5" with a 39" full bust and 35" underbust.
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FREE & EASY RETURNS OR EXCHANGES
Fit Matters. We’ve Got You.
Comfort and fit are everything, especially when it comes to bras+ undies. Helping you discover your next era of intimates is our jam, made easy for you with free returns and exchanges.
Returns of unwashed, unworn items with the tags on are accepted for 30 days and will be refunded to the original form of payment. See our Returns Policy for more details.
Still have questions? Not a problem!
For Style, take our Bra Quiz or Underwear Quiz.
For Sizing, check out our custom Measuring and Calculator.
Still have questions? Shoot us an email at hi@iterationera.com and we can personally assist to ensure you're fitted perfectly!
Bra size chart in Inches
Need to know how to measure your bra size? Click Here!
| FULL BUST - UNDERBUST = | 1" | 2" | 3" | 4" | 5" | 6" | 7" | |
|---|---|---|---|---|---|---|---|---|
| CUP SIZE | ||||||||
| A | B | C | D | DD/E | DDD/F | G | ||
| UNDERBUST (IN) | BAND SIZE | ITERATION SIZE | ||||||
| 26.5" - 28.5" | 28 | XS | XS | XS+ | XS+ | XS+ | ||
| 28.5" - 30.5" | 30 | XS | XS | S | S | S+ | S+ | S+ |
| 30.5" - 32.5" | 32 | S | S | S | S | S+ | S+ | M+ |
| 32.5" - 34.5" | 34 | S | S | M | M | M+ | M+ | M+ |
| 34.5" - 36.5" | 36 | M | M | M | M | M+ | M+ | L+ |
| 36.5" - 38.5" | 38 | L | L | L | L | L+ | L+ | L+ |
| 38.5" - 40.5" | 40 | L | L | XL | XL | XL+ | XL+ | XL+ |
| 40.5" - 42.5" | 42 | XL | XL | XL | XL+ | XL+ | 1X+ | 1X+ |
| 42.5" - 44.5" | 44 | 1X | 1X | 1X | 1X | 1X+ | 2X+ | 2X+ |
| 44.5" - 46.5" | 46 | 2X | 2X | 2X | 2X | 2X+ | 2X+ | 3X+ |
| 46.5" - 48.5" | 48 | 3X | 3X | 3X | 3X | 3X+ | 3X+ | 3X+ |
| 48.5" - 50.5" | 50 | 3X | 3X | 3X | 3X | |||
Fuller Bust size options are best suited for cup sizes DD through G.
Fuller Bust sizes are indicated with a + at the end of the size, [i.e. 1X+] Fuller Bust sizes feature a band that is 1" smaller than the band of the same size bra in the Standard Size. They have slightly taller side seams, center fronts and deeper cup molding to accomodate extra breast tissue.
Don't see your size here? We continue to add sizes based on community feedback. Let us know what size you need by joining the community.
It's all in the details
Is our Triangle Bra is the best bra fit for you? Check out all the thoughtful features that went into making sure she works just right.
Does she check every box? You be the judge.
✔️ Anti-Slip Straps with Low Profile Hardware
✔️ Triangle – Our Mid-level Neckline
✔️ Signature Hidden Support with Sling
✔️ 94% TENCEL™ Modal / 6% Spandex
✔️ Straight or Adjustable Height Racerback Option
✔️ Plush Hook + Eye with 3 Hooks + 4 Adjustment Rows
✔️ Tagless Label
✔️ Pink Sand, Sienna, Mahogany, Onyx
About our fabric
94% TENCEL™ Modal + 6% spandex
We dig our fabric for many reasons, here's just a few of our top favorites:
2X softer than cotton, tough enough for all day adventures
Natural material made sustainably from regenerative beech trees
50% more absorbent than cotton with odor resistance
Reviews
- MSMonica S.Verified BuyerReviewingTriangle Bra | Pink SandI recommend this productAge Range 35-44Rated 5 out of 5 starsNov 4, 2024So comfortable!
I love the fit, material and style of this bra. The band and cup sizes are perfect and the material is so soft and comfortable. The cut out is really fun and honestly makes me smile every time I put it on! The band quality and the front adjustable straps are the two major differentiators. It’s the most comfortable bra I have and can’t wait to order more!
- LBLibby B.ReviewingTriangle Bra | MahoganyI recommend this productAge Range 35-44Size Purchased SRated 5 out of 5 starsOct 9, 2024Comfortable, smooth and supportive!
The bra is exceptionally comfortable, with breathable, smooth materials that make it ideal for all-day wear. I normally wear a 32D and ordered the Small.
Despite being wire-free, this triangle bra provides a really nice amount of support. The wide band under the bust keeps everything securely in place and the ups have plenty of coverage for my shape. It’s perfect for those who prefer a more natural look and feel while still wanting a bit of lift.
IiterationFeb 25, 2025Libby, you just made our day! 😊
We’re so happy to hear that our Triangle Bra is hits all the marks for comfort, support, and that natural look you love! Knowing that the breathable, smooth fabric keeps you comfy all day long—and the wide band gives you that perfect, secure fit—it means the world to us.
Thank you for sharing your experience and for trusting us with your comfort. We love having you in our community! 💜
- SRStephanie R.Verified BuyerReviewingTriangle Bra | Pink SandI recommend this productAge Range 65+Size Purchased L+Rated 5 out of 5 starsOct 10, 2024Great
Very comfortable. No pinches. Wore it all day the first day… amazing
- HWHeidi W.Verified BuyerReviewingTriangle Bra | MahoganyI recommend this productAge Range 35-44Size Purchased MRated 5 out of 5 starsNov 12, 2024Never knew what a $68 bra was like...IT IS WORTH IT!
I have never (NEVER!) bought myself a nice bra. BEEN SERIOUSLY MISSING OUT! So well made, such great attention to detail, and fits amazing. Super comfy, practical but I still feel 'pretty'!
- CBClare B.Verified BuyerReviewingTriangle Bra | Pink SandI recommend this productAge Range 45-54Size Purchased M+Rated 5 out of 5 starsOct 18, 2024The fabric is luxurious
I am so happy with my purchase of this bra — I bought it in two colours! The fabric is so smooth and luxurious, and it's a super comfortable bra — and supportive too. I will be buying more of these for sure. They're my new go-to!