This cable means that you can connect, charge, & sync your iPhone, iPad or iPod efficiently to & from your Mac or Windows PC. You may also use it with a Charger PRO 4 to charge your USB (Universal Serial Bus) devices with greater convenience. Fast Charging Speed Its thick copper wire with aluminum Mylar shielding means that you can fast charge your Apple devices. Excellent Stability Reliable signal & data transfer is guaranteed thanks to its thin copper wire with aluminum Mylar shielding.