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900 B-Fast Swimming Trunks Men's

Sale price: $10.00 Regular price: $19.99

Men's trunk-style swimwear, designed using the best fabric to ensure excellent chlorine-resistance and optimal comfort.

Color: Select a color
Size: Select a size
Size Guide

This product runs small

Sale price: $10.00 Regular price: $19.99

Free shipping over $49

Final Sale: No returns or exchanges

Free returns

Free pickup

San Francisco, 735 Market St. Options

Select an available color and size to see options.

Model: 8648322

Product Videos

Product Features

A photo of the 900 B-Fast Swimming Trunks Men's in use
A photo of the 900 B-Fast Swimming Trunks Men's in use

900 B-Fast Swimming Trunks Men's | Our design teams have developed these briefs for the swimmer looking for a classic shape and who needs support.

Men's trunk-style swimwear, designed using the best fabric to ensure excellent chlorine-resistance and optimal comfort.

Chlorine resistant

more than 200 hours of use: recommended for regular use.


Swim trunks provide good support


Easy to adjust around waist using drawstring and a special silicon toggle.

Product Lifestyle Image Gallery

Image Gallery

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Questions & Answers

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Total satisfaction.

Total satisfaction.

no choice in…

no choice in model

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They are narrow in size

It's a good swimsuit but they are too small and too tight.

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Bought wrong size... supposed XXL.. frustrated

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the 2 jerseys that…

the 2 swimsuits I bought fit me well and are pleasant to wear

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I bought the same costume for the second time because I like it so much+

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I had to take 2…

I had to take 2 sizes larger than my usual size.

Basic jersey

Basic jersey

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Good quality

Ideal for the swimming pool. Very good support

Comfortable and convenient

Convenient and comfortable

Good in the pool like…

Good in the pool or at sea

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Size Guide

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Additional Product Information


Main fabric: 78.0% Polyester, 22.0% Elastolefin ; Lining: 100.0% Polyamide


Swimming trunks – side height 3.1”Swimwear should prioritize comfort. It should enable you to move with ease. That is why it is important to choose the shape of your swimwear carefully.The swimming trunks have a classic and timeless cut, providing great freedom of movement, as well as plenty of support.Details are positioned so that they mold to your body shape.


22%- Elastolefin 78% - PolyesterOur engineers have developed a polyester-based fabric and replaced the spandex fibers with fibers that give it sufficient elasticity to ensure user comfort while protecting it against the damaging effects of chlorine. This thread also offers the following benefits:- quick drying. - only loses 3 to 4% resistance throughout its lifespan.- UV-resistance: Colors are more stable.

Aquaresist technology

Products bearing the AQUARESIST label are guaranteed to deliver chlorine-resistance throughout their lifespan. They will keep their elasticity and be resistant to light. For these reasons, they are recommended for regular or intensive pool use.

Determining the environmental impact of our products

The environmental impact of the product is calculated over its entire lifecycle using different indicators. An ABCDE score is provided to enable easy identification of the most environmentally-friendly products when comparing products of the same type (T-shirts, pants, backpacks).Decathlon chose to apply this voluntary environmental labeling system.Web: Sustainability.decathlon.comVideo:

Product testing

Products labeled with AQUARESIST certification are tested under repeated cyclical loading in a pool of chlorinated water for more than 200 hours. No deterioration of elastic strength was observed throughout the test. Unlike a standard swimming product, the product remains intact.

Storage instructions

Store the swim shorts in a dry place.





Superior quality. Unbeatable prices.

For 40 years, Decathlon has delivered the best value in the retail sports industry by offering high-quality, sustainable and cost-effective products.

Decathlon makes the difference
  1. product-research

    Research and development

    delivers high-quality cost-effective products

  2. State-of-the-art production processes

    minimize manufacturing costs

  3. Optimized supply chain

    reduces retail prices

  4. laptop-checkout

    Minimal retail footprint

    lowers overhead and indirect costs


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