As far as I remember Zong only has -153 model as wingle -320 might be newer or older you can determine this by logo blue=old, Green = new, I have cloud devices and the E5573-320 (old blue logo) is the one with antenna ports look at pics, generally these portable devices can connect 8-10 devices.
The reason for selling different devices is the same whoever sells them cheaper in bulk Zong first mifi device was E5573-320 (blue logo) 1. Wide band coverage (tlnr band 5 aswell) 2. 5ghz wifi 3. Antenna ports while the later model -322 have no 5ghz no antenna ports and no 850mhz. Zong has also launched some fiberhome and ZTE devices but were not popular and were phased out, recently they launched some ZTE device (same as Jazz) with no features but very good battery Jazz on the other hand has launched some alcatel device.
Like the wingle you have E8372h has 5/6 different versions for different regions of the world with different band coverage and features.
E8372h-153
E8372h-607
E8372h-608
E8372h-320
E8372h-511
E8372h-517
To leaen more visit this link
Check Huawei E8372 4G LTE WiFi stick images, appearance, Huawei E8372 specifications, antenna, chipset, data rate speed, price and applications, review Huawei E8372 4G Dongle functions and buy Huawei E8372 4G USB Dongle
www.4gltemall.com