FORTIFY ARM SLEEVES Size:XS a Pulse Ox2 sensor uses

a Pulse Ox2 sensor uses light beams at your wrist to gauge how well your body is absorbing oxygen

We've updated the underfoot cushioning to make it feel more comfortable and energetic

Unlike traditional headphones that move and fall out during use

Set-in back pocket

FORTIFY ARM SLEEVES Size:XS a Pulse Ox2 sensor usesFarewell, bare arms. Our Fortify Arm Sleeves provide maximum coverage when youre out in the elements. Wear your SAUCONY pride on your sleeve and get protected while youre at it. FEATURES & BENEFITS LW silicone gripper helps keep arm sleeves in place 50+ UPF in all colors SAUCONY graphic 75% Recycled Nylon 25% Spandex (240g m2)