For reference, here are the SIM card sizes in the market:
(Source: Wikipaedia)
Cellular-enabled Peplink and Pepwave products use the Mini-SIM (2FF) form factor. If your SIM card is smaller, you can increase the size of the card using a SIM card adapter.
Did you know @Alan that a good alternative to a Sim Card adaptor is to get a cheep prepaid SIM Card with the various punch out sizes already cut and just use the size you need? In Australia (as we’d expect most of the world) cellular/mobile carriers and phone shops will have a few of these and some used ones too, they may if you ask nicely give the adaptor to you for free.
Happy to Help,
Marcus 
I know this post is 4 years old, but I just wanted to confirm that the current Max Transit Duo LTEA uses the full-size SIM card(1FF), not the mini-sim(2FF)
thanks
No as per the above graphic all Pepwave / Peplink routers use the 2FF size.
Hello @Carmou57
Very few manufactures (if any) still use the 1FF SIM Card, the majority of the world’s vendors have been using the 2FF for over a two decades and this includes the Peplink|Pepwave|Pepxim models.
The one exemption to @MartinLangmaid comment is the SFE (SpeedFusion Engine), the SFE takes 2 SIMs (one for each modem), each is a Micro-SIM (3FF).
Happy to Help,
Marcus 
