Junior Trunk

£6.30 £9 Save 30%

The Step One trunk, sized for kids.

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Size

Colour Mistle Toes

1
  • Free shipping
  • 30-day First Pair Guarantee
  • Organically grown bamboo viscose soft and breathable
  • 30-day First Pair Guarantee love them or they're free
Description

The ultimate underwear for boys aged 2-14, our trunks are made with all the same high-quality features as our adult collections. They are available in a range of fun colours and prints and feature our classic fabric which wicks away sweat and lets you breathe.

Fit & Fabric
Our Junior Trunk range is made from 95% viscose made from bamboo and 5% spandex. This equals an extremely soft and durable pair of underwear that wicks sweat brilliantly. The sizing is considered "fitted", meaning that if you are in between sizes, we would recommend sizing up.
Shipping

We aim to dispatch your order 1-2 business days after placing your order.

Free shipping, no minimum spend.

UK Mainland: approx. 2-3 business days after dispatch. International shipping is available and calculated at checkout.

Returns & Guarantee

We are so confident you'll love your Step Ones, we'll give you a full refund on your first pair if you don't like them for whatever reason, within 30 days.

Unworn items in original packaging can be returned or exchanged within 30 days of delivery.

We Science'd Underwear

We didn't just make underwear. We reinvented it. Now in kids sizes.

Ultra Soft Bamboo

Made from viscose made from bamboo — super soft and comfortable, with no itchy tags or scratchy seams. Happy kids mean happy parents!

Safe For Sensitive Skin

Our bamboo material is naturally hypoallergenic and antibacterial, meaning all kids have to worry about is where they are going to play next!

Built For Play

Reinforced stitching and high-quality bamboo fabric made for kids who can't sit still — they withstand endless adventures (and repeated washes).

Greg Taylor - CEO & Founder
Greg Taylor - CEO & Founder
26M+
Pairs Sold
65K+
5-Star Reviews
2M+
Happy Customers
Trustpilot

Trust Score 4.5/5

Real Results from Real Customers

30 Days

First Pair Guarantee

Love them or they're free. If your kids don't love their first pair, we'll give you a full refund.

Risk-free trial
Full refund

Frequently Asked Questions

Our kids range is made from high-quality, organically grown Bamboo Viscose with a touch of spandex. It's incredibly soft, breathable, and moisture-wicking — no itchy tags or scratchy seams.
Yes! Bamboo viscose is naturally hypoallergenic and antibacterial, making it gentle on even the most sensitive skin.
The Girls Shortie comes in Ages 6-7 through to Ages 12-14, and the Junior Trunk covers Ages 2-3 through to Ages 12-14. Use the Find my Fit guide on this page to match your child's measurements to the right size.
We are so confident your kids will love their first pair of Step One underwear that if they don't, you can keep them and we'll give you a full refund. No questions asked. This applies to your first single pair purchase.
Machine wash cold with like colors. Tumble dry low or line dry in the shade. Do not bleach, iron, or dry clean to maintain the quality of the bamboo fabric.