Does this mount at my factory bed rails?

Yes — it attaches at your truck's factory mounting points along the bed rails. No drilling or drilling adapters needed.

Can I open this cover one panel at a time, or do all three fold back together?

All three panels fold as one unit and stack against the cab when open. You can't deploy just one or two panels independently.

Do I need to prep or paint this before installing?

The tonneau arrives ready to install. No sanding, priming, or painting required — bolt it on and go.