SDX55M

The Qualcomm Snapdragon X55 5G Modem is the baseband chipset used in the iPad Pro (11-inch) (3rd generation), iPad Pro (12.9-inch) (5th generation), 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) 14.5          (Build 18E199) 14.5.1        (Build 18E212) 1.70.03    14.6 beta      (Build 18F5046e & 18F5046f) 14.6 beta 2   (Build 18F5055b) 1.71.00    14.6 beta 3    (Build 18F5065a) 1.71.01    14.6 RC        (Build 18F71) 14.6 RC 2     (Build 18F72) 14.6          (Build 18F72) 1.70.03    14.7 beta      (Build 18G5023c) 1.80.00    14.7 beta 2    (Build 18G5033e) 1.80.01    14.7 beta 3    (Build 18G5042c) 14.7 beta 4   (Build 18G5052d) 1.80.02    14.7 beta 5    (Build 18G5063a) 14.7 RC       (Build 18G68) 14.7          (Build 18G69) 14.7.1        (Build 18G82) 14.8          (Build 18H17) 14.8.1        (Build 18H107) 2.03.01    15.0 beta      (Build 19A5261w) 2.06.00    15.0 beta 2    (Build 19A5281h & 19A5281j) 2.07.01    15.0 beta 3    (Build 19A5297e) 2.08.01    15.0 beta 4    (Build 19A5307g) 2.09.05    15.0 beta 5    (Build 19A5318f) 2.09.10    15.0 beta 6    (Build 19A5325f) 15.0 beta 7   (Build 19A5337a) 15.0 beta 8   (Build 19A5340a) 15.0 RC       (Build 19A344) 15.0          (Build 19A346) 15.0.1        (Build 19A348) 15.0.2        (Build 19A404) 2.10.00    15.1 beta      (Build 19B5042h) 15.1 beta 2   (Build 19B5052f) 2.11.01    15.1 beta 3    (Build 19B5060d) 2.11.02    15.1 beta 4    (Build 19B5068a) 15.1 RC       (Build 19B74) 15.1          (Build 19B74) 2.21.01    15.2 beta      (Build 19C5026i)