Ergodyne TREX 6310Xlarge ice traction device contains aggressive tread connecting mid-foot/heel stud for support and reflective pull-on tab for extra visibility. Ice traction device is ideal for construction/roofers/trades. Adjustable Ice Traction Device. Black. Size: Extra Large (11-13). 10 rugged, heat-treated carbon steel studs for tenacious grip & stability. Adjustable cord cinches tight for a secure fit. Stretchable rubber for fit and easy on/off. Aggressive tread connects mid-foot and heel stud zones. Reflective pull-on tab adds enhanced visibility. Flexible to -40F (-40C). Size: (11" - 14"). Material: Heat-treated carbon steel. Applications: Road construction, construction, roofers, trades, installers, contractors, delivery/service, landscaping, utilities, logging, ice ballet. Flexible to -40 deg F. 8 rugged, delivers tenacious grip and stability for shoes and boots. 6301 replacement studs sold separately. Water repellent - designed to resist water for dry comfort. Hand washable. Ergodyne TREX 6310Xlarge ice traction device has adjustable/tight cord cinches for exact fit/comfort and features 10 rugged heat-treated carbon steel stud that offer grip/strength.