Durable Material: This retractable power cord reel is constructed of hard impact polypropylene enclosed spring-driven case and Premium commercial 3C SJTOW cables are resistant to Acids, Alkalies, Ozone, Water,Oil and Kinking; Operable and flexible in the extreme conditions of -58°F to 221°F (-50°C to 105°C) Durable Design: Constructed of Slow Retraction Technology and Auto Guide System for orderly rewind; Utilizing an improved ratcheting, locking the cord at any desired length; Adjustable cable stopper prevents the connector from hitting the case during retraction