Extension cords extending the length of an existing power cord; This 3-prong CLOSING HOOK extension cord is rated for Indoor Extension cord. Use when power extension is needed. The indoor extension cord connects to an existing cable or power strip or a standard 3 prong 120V AC outlet receptacle AUTOMATIC CLOSING HOOK Designed to minimize tripping or stepping on your Extension cords. Extend your reach such as your pc power cord or any electrical cord or use it as an outlet extension, this grounded heavy-duty extension cord will give you more than enough power