Roof Width on a full size topper (Ram 1500)

Can someone please share the width of the roof on a full size TOPPER, edge to edge? I’m curious whether the RTT is a perfect fit, or if it’s narrower than the topper.

I’d like to install a topper and RTT on my 2024 Ram 1500 with a 6’4" bed, but can’t find any pics or dimensions of that exact setup.