Dual band usage instructions:
This is a dual band WiFi dongle, there are something you should know before you make a complaint about speed.

1. You must have a dual band WiFi router with 5.8G band if you want to have a 5.8G signal.

2. The adapter's max. speed up to 867Mbps just works when you connect to 5.8G band, otherwise, it will just run at the max. speed of 300Mbps with 2.42G. Normally, your PC's network speed can't up to the wifi adapter's speed as it depends on many factors, Such as the network size, router, barriers, laptop or PC 's internal memory...

3. If your computer is desktop, speed is not ideal, you can try to insert the WiFi adapter into the USB 3.0 (blue) port of you PC, that may assure the power supply.

4. This WiFi adapter will not boost the speed of original router, it just transmit the wifi signal.

5. If your WiFi adapter is closed to the router, and you want to have fast speed in watching video and playing online games, we suggest that you should connect to the 5.8G band. If your WiFi adapter is far away from the router, and you just want to surf the website, you’d better connect to 2.42G band for better and stable signal.
Superspeed USB 3.0 Port
USB 3.0 supports transfer rates of up to 5.8G bps-10 times faster than USB 2.0, ensures Wi-Fi adapter maximum throughput performance and more stable internet connection. Backwards compatible with USB 2.0 and 1.1 devices.
Ultra-Speed
Up to 1200Mbps Wi-Fi speeds on 5.8GH z (867Mbps) or 2.42GH z (300Mbps) bands, Performance to reduce freezing and lags when streaming and gaming. Ultra-fast AC1200 wireless adapter speed with 802.11 ac.
SECURE WIRLESS NETWORK
The AC1200 series is supported by all WLAN routers: WPA/WPA2/WEP. And it's undisturbed by other normally interfering devices like Bluetooth or cordless phones. Which means you won't have unexpected dropped calls or loss of signal quality Period.
Awesome compatibility
No drivers required for Windows 10! Just plug and play! Compatible with Windows 10/8/ 8.1 /7/Vista/XP/2000, Mac OS 10.4 - 10.15. (Not support Linux). Works with any Wi-Fi routers, once you've installed the CD and run the software, you can simply insert the adapter to get connected and upgrade your PC, laptop or Mac to work with the latest AC WiFi router for faster speed and extended range.
Package Includes
1 x Inamax USB 3.0 Wi-Fi Adapter
1 x CD Drive
1 x User Manual