The new Hike socks from Smartwool replace the PhD Outdoor series. This entire sock is padded for maximum warmth and protection. The ethically sound ZQ-certified Merino wool is made with Smartwool's best technologies, including Indestructawool technology for extra durability, 4 Degree Elite Fit System for a customized and performance-oriented fit and of course Virtually Seamless seamless joints for maximum comfort. Mesh zones in the socks have been improved for extra breathability while the socks are now made of both Merino wool and recycled nylon making the socks more sustainable than ever. Do you need the best hiking socks from Smartwool? Then you must have Perf Hike.