Heather Gray | DiamondCool™ Performance Men's Long Sleeve T-Shirt

Full-Coverage Arm Protection Without the Heat Trapped Inside

Get the total sun defense of a long sleeve with the refreshing feel of air conditioning. The DiamondCool Men’s Cooling Long Sleeve Performance Shirt is designed for high-endurance athletes and outdoor professionals who need full arm coverage but refuse to overheat. It’s light, unrestricted, and actively fights the summer sun.

Patented 58°F Thermal-Drop Technology

Stop wearing heavy layers that turn into sweat-boxes. Our patented cooling fabric uses an advanced, chemical-free technology activated entirely by moisture. The moment you break a sweat or mist the shirt with water, the fabric fibers drop as low as a chilling 58°F (14°C), lowering your skin temperature and keeping your stamina locked in.

Certified All-Day Sun Defense (UPF 50+)

Block out the burn. With a certified UPF 50+ rating, this performance shirt acts as a permanent shield, deflecting 98% of damaging UVA and UVB rays. Enjoy total arm, chest, and back protection during long trail runs, open-water paddles, or back-to-back shifts under the direct sun.

Eco-Friendly, American-Made Engineering

• Repreve® Sustainable Fabric: Knit from recycled plastic bottles, our premium eco-fiber helps clear waste from global waterways while providing an incredibly smooth, durable, and lightweight fit.
• Crafted Domestically: Proudly cut and sewn In the USA from premium imported components, guaranteeing elite athletic stitching that won't give out during intense movement.

Technical Features & Benefits

• Instant Activation: Fabric drops as low as 58°F when damp with sweat or water.
• Maximum UV Block: Non-chemical, permanent UPF 50+ protection.
• Sustainable Quality: 88% Repreve recycled performance polyester.
• Zero-Distraction Fit: Classic crewneck cut designed to move seamlessly without chafing.
• Anti-Odor Defense: Natural antimicrobial properties prevent post-workout odor.
• Origin: Made in the USA of imported fabric.