This product was mentioned in
with an average of
You need the adapter to resize your nano sim card. It looks like this [link] and should have came with your sim card if you still kept it. If you threw it away, you're going to buy an adapter.
As an additional note, the SIM in the 7410 with WWAN option is a Micro SIM, not a Nano SIM. If you have a Nano SIM, you will need an adapter like this:
I just used the sim card that I have with ATT and purchased a sim adapter on Amazon to fit in the slot. Link to the adapter is below. I used the small gold adapter in the pack.