Will this plug into my factory wiring harness?

Yes. This mirror is designed to use your vehicle's existing electrical connectors and switch location. No rewiring required.

Do I need any brackets or fasteners to install this?

The mirror uses factory mounting points. Verify your vehicle's attachment method before purchase—some Commanders use bolts, others use clips. Have your hardware on hand or match existing fasteners.

Can I order just one mirror or do I have to buy a pair?

You're buying a single mirror. Specify driver or passenger side at checkout. Order two if you need both sides replaced.