Name: Air/Knit Sport Brief
Brand: Jack Adams
SKU: 401-389-navy01
Price: 33.5 USD
Availability: InStock

Shirtless man standing in front of a white background wearing a pair of Jack Adams In Air/Knit Sports Brief in army (back view)

$33.50

Shipping calculated at checkout.

Size

Color — Navy

Army

Burgundy

Navy

In stock, ready to ship
Backordered, shipping soon

Air/Knit Sport Brief Performance comfort engineered from nature.

The Air/Knit Sport Brief is built from a premium tri‑blend of 78.2% lyocell, 19.5% wool, and 2.3% elastane, creating a fabric that actively adapts to your body and your environment. It's cool when you're warm, warm when you're cool, and consistently dry—making it the brief you forget you're wearing because it simply works.

Lyocell delivers that signature silky, low‑friction softness, gliding smoothly against the skin. Wool adds natural thermoregulation and odor resistance, keeping you balanced and fresh through workouts, commutes, and long days. Elastane provides the supportive stretch that keeps the brief stable, flexible, and perfectly contoured.

The silhouette is cut for athletic performance and everyday movement, with a supportive front, stay‑put leg openings, and a clean profile that disappears under clothing.

SIZE - True to size

Underwear- Brief
Adaptive tri‑blend — lyocell for softness, wool for temperature control, elastane for stretch
Moisture‑managing comfort that keeps you dry
Natural odor resistance from wool’s performance fibers
Temperature‑adaptive feel that works in heat, cold, and everything between
Supportive sport fit that stays put without riding up
Smooth, low‑friction finish ideal for training, travel, or all‑day wear

A modern sport brief that elevates comfort, enhances performance, and keeps you feeling fresh—no matter how hard you go.

Fabric: 78.2 Lyocell ™,19.5% Wool, 2.3% Elastane.
Machine wash cold water. Air dry, lay flat. Do not bleach or iron.

Get free shipping for US orders over $125+

Discreet packaging: plain poly bag or brown box.

-Shipping Details

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Jack Adams™ underwear and shorts/pants sizing is measured at the waist. To find your correct waist size, measure your torso about one inch below the belly button. To find your size in all of our tops and hoodies, measure your chest around, at approximately one inch below your arm pit.

Size Chart - INCHES

SIZES (inches)	S	M	L	XL	XXL
CHEST	35-37	38-40	41-43	44-47	N/A
NECK	14-14.5	15-15.5	16-16.5	17-17.5	N/A
WAIST	27-29	30-32	33-35	36-38	38-43

Size Chart - METRIC

SIZES (cm)	S	M	L	XL	XXL
CHEST	89-94	97-101	104-109	112-118	N/A
NECK	36-37	38-39	41-42	43-44	N/A
WAIST	69-73	76-81	84-89	91-97	97-109