Will this freshener fit all dashboard air vents?

It's designed for standard horizontal vent slats. Test-fit before purchase if your vehicle has narrow or vertical vents — some aftermarket dash kits use non-standard openings.

How long does the squash scent last?

Longevity depends on vent airflow and cabin temperature, but you're looking at several months of noticeable fragrance. Once scent fades, you can replace the refill cartridge without buying a new clip.

Does this damage or stain the vent slats?

The clip grips without adhesive, so there's no permanent mark when removed. No oils or residue — clean removal every time.