Designed to deliver the maximum abrasion resistance during wear, if you want a sock that will repeatedly last as long as a marathon aerobic pace hike, then our twin pack men\'s Storm Bloc with BlueGuard Aerobic Socks should be at the very top of your outdoor clothing list. High strength filament polymers have been bound and engineered to create our BlueGuard yarn, exhaustively developed and tested to produce a whole range of socks that set new benchmarks in abrasion resistance and durability. Teamed with a cotton rich sock that has ribbed elasticised legs, purposefully positioned terry loop cushioning, reinforced toe seams and extended heels, plus breathable panel inserts, Storm Bloc with BlueGuard Aerobic Socks are highly functional and extremely strong - some 30 times more durable than comparable branded walking socks in fact. All Storm Bloc with BlueGuard socks carry a lifetime guarantee against holes forming.