Patented design prevents "plug barriers" to enable charging/powering up to four iPads * iPhones * Android tablets and phones * MP3 players * GPS * digital cameras * and other USB 2.0/1.1 devices simultaneously without requiring a bulky adapter * Fully National Electrical Code (NEC) compliant tamper-resistant AC receptacles and UL/CUL Listed (E339607) for use in United States & Canada * Smart Power feature only outputs the required charging power for the attached device and energy efficient * spring-loaded Safety Shutter design turns power off to USB ports when connecting cable is removed to prevent "vampire draw" * Requires 16 Cubic Inch Electrical/Wall box. Most boxes are 15 or 16 Cubic inches - This product requires 16 Cubic Inch (or larger). * Includes mounting screws * matching wallplate * and illustrated step by step installation manual