SIM form factors (2FF, 3FF, 4FF)
Updated
Removable SIM cards come in three common sizes: 2FF or mini SIM (25 x 15 mm), 3FF or micro SIM (15 x 12 mm) and 4FF or nano SIM (12.3 x 8.8 mm). Their physical and electrical characteristics are specified by ETSI TS 102 221.
In practice
Industrial IoT SIMs are often sold as triple-cut cards that can be broken out to any of the three sizes.