PortaPow 3rd Gen Data Blocker (2 Pack) Attaches inbetween your USB cable and socket to physically block data transfer / syncing while charging. Compact design won't block neighboring USB sockets. Allows charging without any risk of hacking / uploading viruses, can charge from an office PC even if USB socket has been disabled without breaking IT policy. PortaPow's SmartCharge chip automatically switches between Apple, Universal and Samsung standards to ensure compatibility with your device. SmartCharge supports charging upto 2.4A so the blocker won't slowdown charging and can improve charging speed in some cases. This twin pack has been upgraded to our 3rd Gen design