How long does one Fresh Box last?

Depends on your cabin size and how hot it gets, but most drivers get 3–4 weeks of noticeable scent from a 200G box. The charcoal keeps absorbing odor even after the smell fades, so it's still working for your air quality.

Will this work for a really smelly car?

Charcoal fresheners are best for maintenance—keeping a clean cabin fresh longer. If your car has heavy odor (smoke, pet, mold), you'll want to deep-clean first, then use the Fresh Box to keep it that way.

Can I use this in humidity or wet conditions?

Yes. The charcoal actually absorbs moisture, so it's useful in damp climates or after rain. Just keep it away from direct water spray—place it on your dash or tucked in a cup holder where it stays dry between uses.