1、CSR4.0 - Adopt CSR8510 chip, which is in line with Bluetooth 4.0 technical specification and dual mode transmission. 2、Fully backward compatible with Bluetooth 2.0, Bluetooth 2.1, Bluetooth 3.0 specifications. 3、20m transmission distance - Longer transmission distance (no barrier) with strong signal. 4、3Mbps transmission rate - More stable transmission rate, providing high-speed file and audio data transmission. 5、USB2.0 - USB2.0 interface is more versatile. Features: CSR4.0 - Adopt CSR8510 chip, which is in line with Bluetooth 4.0 technical specification and dual mode transmission. 20m transmission distance - Longer transmission distance (no barrier) with strong signal. 3Mbps transmission rate - More stable transmission rate, providing high-speed file and audio data transmission. USB2.0 - USB2.0 interface is more versatile. Lightweight and ultra-mini & portable. Fully backward compatible with Bluetooth 2.0, Bluetooth 2.1, Bluetooth 3.0 specifications. For CSR original drive management software:  For CSR Harmony drive management software is easy to use, powerful, and supports a variety of application extensions (For Microsoft OFFICE software). Ultra-low latency speed connection, intelligent sleep wake-up energy saving, 24-bit CRC check to resist interference, adaptive frequency hopping to reduce crosstalk. Specification: Type: Bluetooth Adapter Model: BTD-401 Weight: Approx. 20g Size: Approx. 2.2 * 1.5cm / 0.9 *0.6in For CSR8510A10 original chip: Yes Bluetooth standard: V4.0 + EDR dual mode Support Bluetooth CLASS 2: Yes USB interface: USB2.0 standard, downward compatible with 2.0/3.0 standard Operating frequency band: 2.4GHz - 2.483GHz, using FHSS (frequency hopping spread spectrum) technology Operating range in open space: Approximately 20-50 meters Intuitive software operation interface, no complicated settings: Yes Applicable to operating systems: For Windows/ME/2000/XP/2003/VISTA/WIN7/8/8.1 For Windows XP SP2/VISTA/WIN7/8/8.1, it is inevitable to drive, easy to carry! (For WIN8/8.1, it can be connected directly to the Bluetooth headphone speaker, other drivers need to be installed) Data transfer rate: Up to 3Mbps Sensitivity < -85dBM Security: Built-in password and user authorization Power: USB interface directly powered PC/ for Mac: Bluetooth wireless dial-up Internet access (requires Bluetooth mobile phone and other devices) PC: Bluetooth wireless LAN, which can make 8 computers with Bluetooth devices become a small wireless network at the same time. It can also use this function to access the Internet through a Bluetooth wireless base station or a computer with a Bluetooth connector. Base station or computer is connected to the Internet) PC: Bluetooth wireless fax (computer needs to have fax software installed) PC/for Mac: Bluetooth wireless file transfer PC/for Mac: Bluetooth wireless data synchronization PC: Support Bluetooth virtual serial port PC: Support Bluetooth wireless printing PC: Support Bluetooth headset PC /for Mac: support Bluetooth interface (Bluetooth mouse and Bluetooth keyboard) Package list: 1 * Bluetooth Adapter (NO Drive CD) Note: 1. Please note that the package ONLY include a Bluetooth adapter. 2. Please allow slight error due to manual measurement. Thanks for your kind understanding. Connected Devices(Includes all Bluetooth v4.0/v3.0/v2.1/v2.0/v1.1 devices): 1. Bluetooth headset 2. PDA; 3. Mobile phone; 4. Keyboard, mouse; 5. GPS positioning system; 6. Printer; 7. Laptop; 8. Other Bluetooth devices; 9. Desktop computer P.S. For MAC system can only be used in versions 10.2-10.84. Driver Installation: 1. There are three options during the installation process: open, disable, select PC/desktop. 2. Please plug in the Bluetooth adapter after installation.