These are the biggest, slickest slicks that ever slicked.
Zero tread whatsoever. Out of the box, they looked just like innertubes, complete with the tiny, thin strip around the middle of the tire from the mold that birthed them. They are meant to be tubeless, but would also work with tubes.
BUT, they don't work on the back of my bike. I bought a second set of cheap ($600) Chinese carbon fiber rims for my fat tire bike, so I could swap from dirt knobbies to road slicks, without the messy hassle of changing tubeless tires.
At the rear, the 4.5" doesn't quite clear the seatstays, though you can see in the picture that the same tire works on my front wheel. But also, these slicks may be somewhat defective and I don't know if it's me, the rims, or the tires that are the problem: the rims have a somewhat unusual cross-section (without enough of a valley in the middle) that makes it hard to get the tires on and off. When inflating, I can't get the bead to get up against the inside of the rim- I think it's a tire/rim size mismatch- with the tire being just a little too small for the rim. Even with soapy water, I couldn't get the wheel seated evenly on the rim and the tire wobbled enough to brush against the side of the seatstays. Maybe they'll work better on your rims.
One of them either came with or developed a kink in the bead around the edge- see the picture. That didn't seem to be part of the mounting problem, though, and if that is the thing that prevented it from working as a tubeless tire, it should still work with an innertube. I got these 4 or so years ago and tried mounting them and gave up and they hung out in the basement since.
So, they may or may not work for you but it only costs a buck a tire to find out. $65 originally, and they don't seem to make them like this anymore, for some reason.