Screen shot of Huawei Data Card E303C being used on Apple Laptop MacBook Pro.
HUAWEI Mobile Broadband E303C Dongle (Internet Device) can not be used for Mac (Macintosh) Operating System (OS). They (Huawei Technologies CO., LTD) have clearly mentioned on Huawei's official website huaweidevice.co.in that Huawei Data Card supported operating system are Linux (Driver Support), Windows XP, Windows 7 and Windows 8. Huawei Technologies CO., LTD did not make Huawei Dongle for Mac but I can use it for Mac thanks to USB Hub.
I used my Belkin USB Hub as you can see picture of Belkin USB Hub below, I have connected my USB Hub to Apple Laptop MacBook Pro USB Port, and then I've connected Huawei Data Card E303C to Belkin USB Hub, soon after I have connected Huawei Dongle to USB Hub, it quickly detected the device and I installed its Driver from device as instructions given and it works. Belkin USB Hub is very handy.
Thanks to Belkin USB Hub, Huawei Data Card E303C is working fine on Apple Laptop MacBook Pro.
Note: Any USB Hub will do.
Huawei Technologies CO., LTD (Made in China).