NM: Older card, full slot form factor, data only.
VWIC: Newer card, small WIC form factor, more features, data and voice.
VWIC2: Latest type, like VWIC with even more features.
Hope this helps, if it does please rate post using the scrollbox below!
You are very welcome and good luck with your project.
Wouldn't you mind rate useful posts as it is customary in this forum?
Thanks!