DUI Mens Duotherm 300 Drysuit Undergarment Vest

Quick answer: The DUI Duotherm 300 Vest is a men's drysuit undergarment layer made from heavy stretch fleece (560 g/m²) with a pill-resistant, watershed outer jersey and a plush velour lining. DUI says it adds about 5 degrees of extra insulation when layered.

Why bigger divers look at it

Drysuit undergarments need to stretch, because they live in a tight space between you and the suit. DUI builds this vest from all-way stretch fleece, so it moves with a broad chest and shoulders instead of riding up. A vest also keeps your core warm without adding bulk to your arms, which helps when you're reaching for valves or a drysuit inflator.

What you get

• Heavy stretch fleece, 560 g/m²
• Pill-resistant, watershed outer jersey
• Plush velour lining
• Zipper closure and hand-warmer pockets
• Part of DUI's ActionWear Pro DiveWear line
• Men's sizes XS through 2XL

Before you buy

Try your drysuit on over the vest and your other layers before the dive. If the suit gets tight across the chest, you may need a different layering plan. Read Drysuit Wetsuit Comparison: Which Fits Your Dive?. More options: Extended-Size Wetsuits, Drysuits & Dive Apparel (XXL and Up).