Do I need adhesive or fasteners to install this?

The glass seats into your factory mirror housing — mounting method depends on your mirror assembly design. Test-fit first to confirm how it seats, then use adhesive or fasteners appropriate for your application.

Will this work if my mirror housing is cracked?

This is glass only — it replaces the lens, not the housing. If your mirror case is damaged, you'll need to repair or replace the housing separately before installing new glass.

Can I return this if it doesn't fit?

Contact ModSupply directly about returns. Because mirror glass is vehicle-specific, confirm left vs. right side and your exact model year before ordering to avoid a mismatch.