SDX55M

The Qualcomm Snapdragon X55 5G Modem is the baseband chipset used in the iPhone 12 mini, iPhone 12, iPhone 12 Pro and iPhone 12 Pro Max.

This is the first baseband chipset in an Apple Mobile Device to support 5G communications, capable of providing download speeds as high as 7.5 Gbit/s.

it is also known as  in firmware.

Known Firmware Versions
1.00.03-5  14.1           (Build 18A8395) 1.14.04    14.2 beta 4    (Build 18B5083a) 1.14.05    14.2 RC        (Build 18B91) 14.2          (Build 18B92 & 18B111) 1.14.06    14.2.1         (Build 18B121) 1.31.02    14.3 beta      (Build 18C5044f) 1.31.03-4  14.3 beta 2    (Build 18C5054c) 1.31.03-5  14.3 beta 3    (Build 18C5061a) 14.3 RC       (Build 18C65) 14.3 RC 2     (Build 18C66) 14.3          (Build 18C66) 1.41.00    14.4 beta      (Build 18D5030e) 1.42.02    14.4 beta 2    (Build 18D5043d) 1.42.03    14.4 RC        (Build 18D52) 14.4          (Build 18D52) 14.4.1        (Build 18D61) 14.4.2        (Build 18D70) 1.57.02    14.5 beta      (Build 18E5140j & 18E5140k) 1.60.01-2  14.5 beta 2    (Build 18E5154f) 1.62.02    14.5 beta 3    (Build 18E5164h) 1.62.09    14.5 beta 4    (Build 18E5178a) 1.62.11    14.5 beta 5    (Build 18E5186a) 14.5 beta 6   (Build 18E5194a) 14.5 beta 7   (Build 18E5198a) 14.5 beta 8   (Build 18E5199a) 14.5 RC       (Build 18E199)