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Size Guide

Size AU/NZ UK US
XS 8A
8B
10A
30A
30B
32A
30A
30B
32A
Small 8DD
10B
10C
10D
10DD
12A
12B
30DD
32B
32C
32D
32DD
34A
34B
30DD
32B
32DD
32C
32D
34A
34B
Medium 12C
12D
12DD
12E
14A
14B
34C
34D
34DD
34E
36A
36B
34C
34D
34DD
34DDD
36A
36B
Large 14C
14D
14DD
14E
16A
16B
16C
36C
36D
36DD
36E
38A
38B
38C
36C
36D
36DD
36DDD
38B
38C
XL 16D
16DD
16E
18A
18B
18C
18D
38D
38DD
38E
40A
40B
40C
40D
38D
38DD
38DDD
40A
40B
40C
40D
Size AU Size UK Size Waist (cm)
XS04-0600-0260
Small08-1004-0664
Medium12-1408-1068
Large16-1812-1472
XL20-2216-1876
2XL24-2620-2280
Size Waist (cm) Waist (in)
2XS / (Size 4/8)53-5621-22
XS / (Size 8/12)57-6623-26
Small67-7627-30
Medium77-8631-34
Large87-9735-38
Extra Large98-10739-42
2XL108-11543-45
3XL116-12546-49
4XL126-13350-52
5XL134-14353-56
6XL144-15057-59
Size Waist (cm) Waist (in)
4XS (Age & Size 3-4)40-4415-17
3XS (Age & Size 5-6)45-5118-20
2XS (Age & Size 7-8)52-5921-22
XS (Age & Size 9-11)60-6923-26
S (Ages & Size 12-14)70-7627-30
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[EXP-A] Men's Bamboo Underwear Boxers in black and grey - Model:SkylerClassic Best SellerBoxer Brief - Burgundy & Black - Bamboo UnderwearNew - Rouge Noir
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Boxer Brief Sport Cloud Mesh - Black - Bamboo Underwear - Model:BabaCloud Mesh SportBoxer Brief Sport - Nightriders - Bamboo Underwear - Model:Ivan MBest Seller
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[EXP-A] Men's Bamboo Underwear Boxers in all black - Model:SkylerBest SellerBoxer Brief - Vivid Blue - Bamboo UnderwearFresh Colours
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[EXP-A] Women's SmoothFit Thong - Espresso-Tini - Bamboo Underwear - Model:ElkeSmoothFit ThongWomen's SmoothFit Padded Bra - Chic Champagne - Bamboo UnderwearSmoothFit Bra
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[EXP-A] Women's Underwear Body Short in Black - Model:YolandaBody ShortWomen's SmoothFit Boyleg - Pink Beige - Bamboo UnderwearBoyleg
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Women's Period Full Brief - Bamboo Underwear - Model:ArmaniPeriod Full BriefWomen's Period Bikini Brief - Bamboo Underwear - Model:ArmaniPeriod Bikini Brief
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Women's SmoothFit Bikini Brief - Navy - Bamboo Underwear - Model:EmilyMatching SetsNudes
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Step One is a leading direct-to-consumer online retailer for underwear. Step One offers an exclusive range of high quality, organically grown and certified, sustainable, and ethically manufactured underwear that suits a broad range of body types. Step One has transformed the underwear market with an innovative design and cult-like following and has quickly grown into a multinational company operating in Australia, the US and the UK.

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