More dually wheel questions.

[CG]

First off I just realized I’m woefully short on lug nuts. Ideas on where to get this kind?

Secondly I have no real idea on the reasons for these rings. The tires I purchased are of a size I should not need any sort of spacer between the rims to avoid the rubber rubbing against each other. Also these nubs? My new steel 16 inch rims have no provisions for them. Ideas on where to get these rings?

I’m new to the dually world and apparently I’m a crappy google searcher because I’m missing the info out on the www. Thanks for any help.