This USB-Bug USB Tester and Data Masker from Triplett is designed to test the power, voltage, and current of USB 2.0 and USB 3.0 charging ports. It displays the amp hours (Ah) and milliamp hours (mAh) that have passed through the tester and displays this information as a cumulative number, which is useful when determining how quickly and effectively a portable battery charger is working. The USB Bug has a built-in Smart Chip for Intelligent Charging that allows it to determine the safest maximum current your PD can accept. It can charge your phone or tablet up to 50% faster than aftermarket chargers. There are two USB out ports. The top port, called the unmasked port, allows data to transfer while charging. The bottom port, called the masked port, blocks any data from being transferred. You can use the masked port to charge your phone or tablet without having to worry about anyone accessing your data.