USB Bluetooth Dongle v4.0, Class 2 supports latest Bluetooth technology version 4.0, called ”Smart Ready”. It is highly required, if user want to connect a low power Bluetooth 4.0 device (e.g. smart watches, heart rate monitor) with their notebook, netbook, ultraboook etc. Most of current computers and millions of existing computers do not support bluetooth 4.0. Users must have this dongle to upgrade their systems, if they want to connect with Bluetooth 4.0 hardware!