Ok, My husband works in Roofing & Construction for 20 years, and is VERY dark skinned where he's exposed due to the sun, (he is mexican) so I got these to protect his skin, he works in the sun the entire day, and he loves them! So we are ordering another 5pk today. He says these keep his arms completely cool all Day which he LOVES,Also has the UV block (which I love)Before we found these he usually wore regular longsleeve shirts, but they themselves do not block all the UV rays and defiantly do See full review