Narrow / Wide Band iDirect router Determination

This might be a dump question. I have two iDirect 5150 routers and I was asked the question if they are Narrow or Wide band routers? I believe this is in regards to 64Kbps and 200Kbps upstream IP data rates.

I was under the impression that this only affected the 3100 series routers.

Can someone clarify this for me and if so how do determine which band the routers are configured.

Best Regards;