The Smartwool PhD Run Ultra Light Micro Socks are highly recommended for women ultrarunners looking for a combination of comfort and performance. These socks are made with a blend of merino wool and synthetic fibers, offering moisture-wicking and temperature regulation properties. The ultra-light cushioning provides minimal bulk while still offering impact protection. The 4 Degree Elite Fit System ensures a secure and comfortable fit. With their high-quality materials and design, these socks are a top choice for women's ultrarunning.