Please provide a list of Roku devices and the connections??
Roku Express = XXg wirless connetion
Roku Ultra = XXg and hard wired connection
A list of all of them would be great, since I have a variety of them in my house.
This would be helpful when you look at your network connections to insure all your devices are getting their optimum connections.
Are you asking about which wifi band, 2.4 GHz or 5 GHz, each model can connect to? This chart may help you:
Any models NOT listed as dual band are 2.4 GHz only.