Not the most breathable but not too bad. Adhesive stains are visible immediately after unpacking. In addition, the white foam creases even before I put them on. Black rubber pads on the underside are glued slightly off-center. The logo is disgusting. The insole is very comfortable and the overall design looks amazing on the charcoal gray and blue version I bought. I'm updating with DurablilityUpdate 1: took her on a hike up Mount Rainier over fairly difficult terrain. Lots of gravel and lots of sharp wedge shaped stones. To be honest, although the foam is cracking and crumbling, this is perfectly normal. 5 miles walk and they are perfectly fine.