Extract Huawei E3276s-150 Firmware 21.491.03.00.00 on your computer
Install the Firmware update file for Huawei E3276s-150 downloaded from Huaweiflashfiles.com
Follow the procedure for updating Firmware that is given in Package.

Huawei Flash File | Size: 50.34 MB
Version: 21.491.03.00.00
Operator:Universal
Operating systems: Windows 7/8/10/XP/Vista
Huawei E3276s-150 Firmware Download