what is 2ff and 3ff sim?
SIM Card sizes. ... Mini SIM (= 2FF): 25 x 15 mm. This used to be the standard for many years from 1996 and still is the most common size around. Micro SIM (= 3FF): 15 x 12 mm. Beginning with iPad and the iPhone 4 in 2010, this smaller size was introduced and more and more new devices are using it now.