Bought 9 pairs to replace most of my mismatched pairs. They're good, you feel they'll be too tight pulling them up your ankle, I'm a 44 using 2XLs, but once they come up your calf, they're surprisingly comfortable. The length and design are fashionable right now, and the material is light and nice against your skin, not itchy or scratchy, rather soft. If you have very thick calves the top of these might be tight on you, though. Navy looks almost black. My concern is durability, I had one sock develop a hole on my first ride on the toe edge, I don't have long nails or hotspots on my shoes, and another failed after 3 rides ripping along a seam on the side of the foot. Castelli stands behind their products and their service is great, but beware, quality or durability issues may arise. Might be the price you pay for having very light socks.
Very nice socks. Italian made and they both look and feel great. They are a bit snug (read "aero"), which I suppose is the point since the UCI limits the length pro riders can wear in races. I wear a size 42 Fizik shoe, and I ordered the L/XL size sock. I was really surprised how tight these socks fit on my smaller, narrow feet - so be warned to order a larger size if you're a bigfoot. Overall I am very happy with these socks and will definitely order more pairs as I need them.
I live in southern Arizona where the temperature goes into 3 digits and quite often high 80s thru 90s. The lightweight super breathable construction of these socks are second to none. Did I also say they are quite stylish with an extra tall cuff ?
Grabbed a pair of these as I'd heard they compared favorably to Rapha's Pro Team socks, plus as these were on sale they were almost half the price. These Castellis are really lightweight with next to zero stretch, making for a PITA to get them on, you definitely want to take it slooooow and easy. Even doing that though they are very VERY fragile - my pair ripped on my 2nd wearing of them (under same use conditions my Raphas, Giros and Darn Toughs). Would not buy again.