Do I need any fasteners or adhesive to install this?

Mounting hardware and attachment method are not specified—test-fit the lens in your mirror housing first to determine whether you'll need fasteners, adhesive, or existing clips. Have your service manual handy to confirm the original mounting style.

Can I use this on the left side too, or is it right-side only?

This is a right-side (driver's side) mirror glass. If you need both sides, order a second unit for the left. Verify your vehicle's mirror orientation before checkout.

What's the return window if this doesn't fit my mirror housing?

Contact ModSupply customer service directly for return eligibility and process details—they'll walk you through it based on your situation.