This is the BEST summer jacket I have even owned, and I have owned many... This jacket is an armor that breathes, in other words and protects you in comfort. I am always too hot in the summer even with mesh jackets, but this one has a lot of air flowing through it so it is extremely comfortable even in hot and humid weather. It is a heavy jacket, but when you wear it it feels very light. It is extremely well made and pretty much true to size. I am 5’6” tall and 155 lbs and the size large is perfect!! Not too tight not too loose. Just perfect. I ABSOLUTELY LOVE IT!!I love this jacket. I live in Florida and prefer to ride with my arms covered for sun protection as well as protection if I were to ever go skidding across the road. No one plans on that happening, and I hope it never does, but with all of the distracted drivers sharing the road with us, a bump could easily send me flying off the bike. This gives me some protection against road rash. And because it’s made by Klim, I know the quality is good. I’m able to wear it during our hot humid weather. The mesh breathes. And I love the zip pocket on the left sleeve for an ID card, and I keep my gas card handy there. I’ve received many compliments from fellow bikers. I was originally trying to find a high visibility mesh jacket from HD, with no luck. Two friends recommended Klim, so I got it and I love it.I bought that jacket for summer riding in hot, humid North Carolina. It works really well keeping me cool even when standing at the light in full sun. I was riding in 90+ degree and no sweating. I also like the color and high visibility. The jacket is well made and I didn't had any problems with sizing, I took L as this is my usual size and it fits perfect. It feels light and it's comfortable, I barely know I have a jacket on.KLIM jackets are quality! I have the Altitude in Size Large but needed this style in the XL due to it being shorter and a bit snug around the bottom when sitting…So the XL is a bit loose in chest area but still very comfortable. Upgraded the protective inserts through KLIM directly. Don’t get why the upgraded are standard on the men’s jackets but not on the women’s. Overall a great jacket for warm weather.This jacket has a very good quality all around from the padding to the mesh lining. I am a medium, and the overall fit was great, with my arms down. I tried riding with the jacket but it was extremely uncomfortable with such a strong pull on the arms. I returned the jacket for a size large and that was way too big. The jacket gives the option for a little room around the waist with a zipper to unzip on both sides, but nothing to taper in, so if it’s not a snug fit around the waist you’re screwed. The large did not fit my waist or my frame but I was able to raise my arms. I returned this and went to a motorcycle store to try on jackets and ended up getting a men’s equivalent to this but brand name alpinestars. I had their gloves anyway and I ended up loving the fit and arm range of motion with the alpinestars jacket.Fabulous fit and comfortable. It is not stiff, but not flimsy either. Have already worn it several times in the heat. Not as drafty as I had envisioned, but it does promote air flow.I would say it is a good solid medium in sizing.This jacket is amazing! Worth every penny. I don’t know how I ever lived without mesh. Tough construction, great pockets, chest pocket is key and perfect for the phone. Armor is comfortable and not heavy. It’s also cool because it’s kind of a honeycomb design that the air can get through.Klim has hit a home run with this. Finally a legit jacket for riding! The armor padding is in all the right places. Fits perfectly and even if it doesn’t, it can be exchanged easily.Now I’ve purchased jackets like this before from other companies, but with Klim, they go above and beyond packaging. They don’t fold your jacket. Instead, it comes already hung on a hanger and straightened out. It’s fitted in an oversize box made for this type of garment so you get no creases when it arrives. It’s also paper and plastic wrapped just like the dry cleaners.That alone, makes me happy and they definitely made a great impression on me. Will definitely come back to buy more as needed and for the fam!