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Leakproof Logo Modal Rib Boxer Brief

$35.00 CAD

Buy 3+ Save 15%, Buy 5+ Save 20%

Absorbs about 1 regular tampon

Ultra-soft ribbed modal

Perfect for daily wear

Machine washable

Esther has 38

Esther has 38" hips and wears KNIX M

Esther has 38

Esther has 38" hips and wears KNIX M

Esther has 38

Esther has 38" hips and wears KNIX M

Esther has 38" hips and wears KNIX M

Color: Grey

Size:

True to Size

•

Size:

Size and Fit Guide

Leakproof Underwear is Sales Tax Free in Canada*
Free Shipping on orders $125+

Shipping

Shipping

Processing Timelines

Please allow 1-2 business days for our warehouse team to pack and ship your order. During peak periods such as sales, holidays and product launches, please allow up to 4 business days for us to process your order.

Delivery Time

For the most up-to-date delivery time estimates, please refer to the shipping timeline at checkout. Delivery timelines vary depending on location and do not include processing times.

Shipping Charges

Orders over $125* CAD = Free Shipping (2-6 business days)

Orders under $125* CAD = $12 CAD Shipping (1-3 business days)

Orders delivering to NWT, Nunavut and Yukon are subject to $20 delivery fee.

*After discounts, before shipping and taxes.

First Pair Risk Free for 30 Days

Leakproof Underwear, Risk Free

Returns & Exchanges

Holiday Return Policy
Eligible items purchased online or in stores between November 2, 2026 and December 31, 2026 may be returned through January 29, 2027. All other purchases fall under our 30 day Returns Policy.

Standard Return Policy
New to leakproof? Your first pair is risk free for 30 days. Wear them, wash them, and see how they work for your body. Not right for you? We'll refund the item price (original shipping excluded). Prefer a different size or style? We also offer free exchanges. Just email info@knix.com and we'll take care of you.

Purchased leakproof before? Within 30 days of delivery you can exchange for another size, style, or store credit. We're unable to provide refunds on underwear. If you ordered multiple pairs, please open, wash, and wear one pair only before initiating an exchange.

Still have questions? View our full policy here.

Rewards Members Earn 35 Points

Product Description

Easy-to-wear underwear meets a new, must-have look. Soft modal spandex in a boxer-style silhouette with signature Knix logo waistband—in other words— these are your next favorite pair. Featuring our built-in leakproof technology so that you can use them as backup period protection or on their own on lighter days.

Comfort-First Fit

This boxer style sits at the natural waistline with full bum coverage.

Worry-Free Protection

Our original leakproof technology offers a barely there feel while patented bonded edges help prevent side leaks.

Light Absorbency

Absorbs 1 regular tampon worth of liquid—perfect for light flow days, sweat and discharge, and backup protection for heavy flow days.

Easy to Wash

Machine washable, just like your regular underwear.

Zoom

Esther has 38
Esther has 38
Esther has 38

How to Choose?

Essential

  • • Days you don’t need leak protection. Everyday freshness and moisture wicking.
  • tsp
    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.
  • tsp
    about 8-14 tsp
  • pad
    about 1.5-3 regular pads
  • tampon
    about 4-7 super tampons
  • cup
    about 1.5-3 menstrual cups

Light

  • • Daily freshness. For sweat, discharge, period spotting, or backup protection.
  • tsp
    about 1-3 tsp
  • pad
    about 1-3 pantyliners
  • tampon
    about 1-3 regular tampons
  • cup
    about 0.5 menstrual cups

Moderate

  • • For mid-cycle flow, surprise cough or sneeze leaks, or a really sweaty spin class.
  • tsp
    about 4-8 tsp
  • pad
    about 1-1.5 regular pads
  • tampon
    about 2-4 super tampons
  • cup
    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.
  • tsp
    about 15-20 tsp
  • pad
    about 1.5-2.5 super pads
  • tampon
    about 7-11 super tampons
  • cup
    about 2-3 menstrual cups
PATENTED LEAKPROOF TECHNOLOGY

Built-in protection that feels like nothing at all

Our original Fresh Fix Technology® features a built-in absorbent liner absorbing about 1 regular tampon worth of liquid so you feel fresh and in-control.

Soft Top Layer

Gently wicks away moisture while keeping you feeling fresh and odor-free.

4.2
Rated 4.2 out of 5 stars
Based on 178 reviews
76%would recommend these products
ComfortRated 4.1 on a scale of 1 to 5
EffectivenessRated 4.2 on a scale of 1 to 5
FitRated 0.1 on a scale of minus 2 to 2
Keywords
Keywords
Rating
Ratings
Height
Height
How do you use your Leakproof?
How do you use your Leakproof?
Usual Pant Size
Usual Pant Size
178 reviews
  • Rated 5 out of 5 stars
    2 weeks ago
    My new fave!

    Love these briefs! They are so comfy!!

    TH
    Teresa H.
    Verified Buyer
    Reviewing
    Leakproof Logo Modal Rib Boxer Brief
  • Rated 5 out of 5 stars
    2 months ago
    So comfy

    They are so soft and comfortable.

    JH
    Jorie H.
    Verified Buyer
    Reviewing
    Leakproof Logo Modal Rib Boxer Brief Grey / M
  • Rated 5 out of 5 stars
    2 months ago
    So comfortable and soft!

    Love this boxer for sleep. So soft and comfortable.

    JE
    Jackie E.
    Verified Buyer
    Reviewing
    Leakproof Logo Modal Rib Boxer Brief Grey / L
  • Rated 5 out of 5 stars
    2 months ago
    Th Best fitting Briefs!

    I LOVE these Briefs! It's too bad they're being discontinued. They are the most comfortable, lightweight and durable crotch area.

    AS
    Annie S.
    Verified Buyer
    Reviewing
    Leakproof Logo Modal Rib Boxer Brief White / M
  • Rated 5 out of 5 stars
    3 months ago
    Great boxers just size up if you have a fluffy tummy

    Love the cut and they have a good size gusset just sized up for the tummy

    EW
    Emily W.
    Verified Buyer
    Reviewing
    Leakproof Logo Modal Rib Boxer Brief Black / XL
  • Rated 5 out of 5 stars
    3 months ago
    Comfortable

    The underwear were a gift for my daughter and she says they are very comfortable and loves how they do what she needs them to do .

    JA
    Jodi A.
    Verified Buyer
    Reviewing
    Leakproof Logo Modal Rib Boxer Brief White / M
  • Rated 5 out of 5 stars
    3 months ago
    Boxers

    Love the feel and fit

    BD
    Bonita D.
    Verified Buyer
    Reviewing
    Leakproof Logo Modal Rib Boxer Brief
  • Rated 5 out of 5 stars
    3 months ago
    review

    Good fit and good value

    MH
    Myra H.
    Verified Buyer
    Reviewing
    Leakproof Logo Modal Rib Boxer Brief Black / L
  • Rated 5 out of 5 stars
    3 months ago
    Comfortable

    I like it!

    TS
    Tola S. D. M. S.
    Verified Buyer
    Reviewing
    Leakproof Logo Modal Rib Boxer Brief Grey / L
  • Rated 5 out of 5 stars
    3 months ago
    So soft!

    I bought these to wear in summer under dresses and skirts. The modal material has been my go-to for warm weather bras (and for the heat of peri-menopause). These are way softer than the modal bras or tanks.. I was very pleasantly surprised! I normally wear a small in knix underwear, but find a small fits better in these.

    KM
    Keri M.
    Verified Buyer
    Reviewing
    Leakproof Logo Modal Rib Boxer Brief White / M
  • Rated 5 out of 5 stars
    3 months ago
    SO COMFY

    This is the most comfortable underwear I have EVER worn. I’m obsessed with the modal rib fabric, to the point where I wear this all the time, not just on my period! Obviously should only be worn with a baggier pant, but that’s most of my wardrobe anyway lol

    MA
    Madeline A. S.
    Verified Buyer
    Reviewing
    Leakproof Logo Modal Rib Boxer Brief Grey / M
  • Rated 5 out of 5 stars
    3 months ago
    These are my favorites!

    I ordered three different styles to see which I liked the best. This style is my favorite. I’m sad that I only got to order one pair and they’re being phased out. The fit is perfect for me and I love the fabric.

    AS
    Annie S.
    Verified Buyer
    Reviewing
    Leakproof Logo Modal Rib Boxer Brief White / L

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