The giro hrc merino sock the hrcmerinotrade wool sock has become giro39s most loved sock for riders who demand performance it is now available with a core spun meryl merino wool yarn that adds the soft touch of wool for mountain biking and some warmth for cool weather riding the compressive qualities promote increased circulation with greater arch support and the extra reinforced toe and heel improve durabilty with a 7 cuff height you have protection on the trail and warmth whe