Our most technical sun-protection tee is designed for breathability and durability, making it ideal for long, sweaty, multiday treks where UPF 50+ is critical. The highly abrasion-resistant, UPF 50+ fabric and low-bulk bonded seams are strategically constructed so they can withstand hours of pack rub without breaking down. Bottom line: If you carry only one shirt, make sure it’s Olia.