LTE Modem Connectivity question

I am looking for a modem just like the Netgear LTE Broadband Modem.

My question revolves around the use of a SIM card with the Netgear device on a GSM network.

Can I occasionally remove my SIM card from the phone, insert it into the Netgear device and gain data connectivity?

So far I have received 5 different answers from the AT&T and T-Mobile folks.  Either they do not know or are not experienced enough to provide a factual reply. 

Hopefully the Netgear experts can provide an answer.