newest 5g wireless internet device

If you're talking about the Wireless home phone and Internet, yes. But I doubt you can use the SIM out of your exiting cell phone as the services are not the same.

What model is it?

Select what you want to look at in this link

Great questions, @hmcm! As @spoom2 pointed out, it is possible to connect a landline phone to an AT&T Wireless Internet device (AWI).

Just plug your existing corded or cordless telephone into the AT&T Wireless Home Phone, plug the device into a power outlet, turn on the device, and you’re ready to make or receive calls.

Your voice calls connect to the AT&T wireless network. Also, as @spoom2 clarified, your mobile phone's SIM card will not work if it is removed and inserted into the AWI device. It is recommended that you use the SIM that comes with your device.

We invite you to visit devices tested and approved to work on the AT&T network. Make sure to scroll to the section Wireless Home Phones to find what devices will still work on our network after we phase out 3G in February 2022.

We hope this info helps. Thank you for contacting AT&T Community Forums.

Lar, AT&T Community Specialist

Lar,

I am trying to find out if there is a new 5g home phone and internet device.  My AT&T says I can upgrade but there always is a glitch when I click on upgrade.  I called a store and the rep said he could order one for me.  They dont have at the store but he didn’t know the price.  Is there really a new device for the grandfathered wireless home phone and internet device? If so what is it ?

Check the link previously posted. Per AT&T they no longer support new services for the WHP or AWI

Not sure what “no longer support new services” means. It still supports the Homebase, but  I would like to upgrade.  So there is NO new device for this plan?

The new device is the AWI (AT&T Wireless Internet) and phone model IFWA-40, if you read the link which will take you to the device you see it says "out of stock" and other topics on this issue says they are no longer selling them. The information is all in the links provided 

Do they make a 5G device that has home phone on it for AT&T?

I gave up on the 5G home phone and went with a phone line through my Internet Gateway. Actually called Digital Home Phone service. When set up all I had to do is plug my landline phone into the phone jack in the back. I use an AT&T DLP73410 base with with three remote handsets through the house. The DLP73410 will connect to a 5G phone with Bluetooth, but NO VOICEMAIL.

Digital Home Phone service has Call Blocking, Call Protect, Call Forwarding, and of course Voicemail.