Guide Gear Men's Insect Shield Performance Quarter-zip Shirt Oil Blue XL

Sizing: is relaxed, like in the photo, not a trim fit like a base layer top. I ordered one size up, XL instead of L, because I wasn't sure of the sizing. I could have ordered large and would have still been able to comfortably wear this Performance Shirt over a shirt. If you want a trim fit, using it as a base layer, you might want to order one size down. I ordered both the Mandarin Red - almost an orange, and Oil Blue - almost a sea foam green. I am very happy with both colors. Insect Shield treatment rocks for protecting against ticks etc. Plus you probably don't have to worry about the treatment washing out before the garment dies - treatment is rated for 70 washings. Wearing Insect Shield treated clothing, Picaridin spray on exposed skin, we haven't had ticks on us in several years. Before we used to get Lyme at least once a year - and we didn't even have any visible bites. We used to soak treat clothing. Treatment worked so well that we now either buy Insect Shield treated clothing. Or send clothing out to Insect Shield for treatment - the pre-packs are the best value.