How long does one box last?

Gel fresheners typically last 4–6 weeks depending on cabin temperature and ventilation. Hotter climates and open windows speed evaporation; sealed cabins keep scent longer.

Can I use both scents at the same time, or do I switch between them?

Both chambers are active simultaneously—you get a blended lemon-orange aroma. Open or close the vents on each chamber if you want to dial one scent up or down.

Will this stain or damage interior surfaces?

Gel formula won't leak or drip under normal conditions. Place it on a flat, stable surface or in a cup holder. If spilled, wipe immediately with a damp cloth.