Every Simbase plastic SIM ships as a multi-size punch-out card: one piece of plastic with three concentric perforations so you snap out the exact size your device needs. This page explains the sizes in the standard, when to use which, and what to do if you need an embedded SIM instead.
The three punch-out sizes
| Form factor | Common name | Length × Width × Height (mm) | Length × Width × Height (in) |
|---|---|---|---|
2FF | Mini-SIM | 25 × 15 × 0.76 | 0.98 × 0.59 × 0.03 |
3FF | Micro-SIM |
| 0.59 × 0.47 × 0.03 |
4FF | Nano-SIM | 12.3 × 8.8 × 0.67 | 0.48 × 0.35 × 0.026 |
2FF
3FF
4FF
The fourth form factor - MFF2 (embedded)
MFF2 is the embedded SIM standard: a tiny solderable chip that's reflowed onto the device's PCB during manufacturing. It can't be removed once installed.
When MFF2 makes sense:
You're an IoT device manufacturer integrating Simbase SIMs at production
The device is sealed, vibration-prone, or in a harsh environment where a removable SIM could work loose
You want a smaller PCB footprint than even Nano-SIM allows
Tamper resistance matters; embedded SIMs can't be physically swapped or stolen
MFF2 SIMs aren't sold off-the-shelf because they're soldered, not socketed. To order, contact sales@simbase.com with your projected volume.
Form factor vs. SIM profile
Two independent dimensions:
Form factor is the physical size and packaging (2FF / 3FF / 4FF / MFF2).
SIM profile is the logical configuration — the colour-coded family that determines coverage, pricing, and underlying technology (Multi-IMSI or eUICC). See SIM Profiles.
Choosing a form factor
| If your device is… | Use |
|---|---|
A consumer smartphone or tablet | 4FF (Nano-SIM) |
A modern IoT router or gateway | 3FF or 4FF — check the tray |
Older industrial hardware | 2FF (Mini) — still common |
Custom-built IoT hardware in production | MFF2 (embedded) |
A consumer smartphone or tablet
A modern IoT router or gateway
Older industrial hardware
Custom-built IoT hardware in production
Common questions
You don't need to. Simbase SIMs ship as a multi-size punch-out card, so you snap out the exact size your device takes. Cutting a SIM by hand risks damaging the chip contacts.
No. Form factor is only the physical size. Coverage, pricing, and network technology are determined by the SIM profile, which is independent of the size you snap out.
A SIM adapter tray will step a smaller SIM back up to a larger slot, 4FF into a 3FF or 2FF holder, for example. The chip itself is unchanged, so the SIM still works.
MFF2 isn't sold off the shelf, because it's soldered onto the board during manufacturing rather than inserted. Contact sales@simbase.com with your projected volume.
Related
SIM Profiles, the different profiles Simbase uses
eSIM, what it is and when to use one
Multi-IMSI vs eUICC, how the underlying tech enables roaming
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