Because that's how long the 2-lb fire extinguisher in your Airstream will last. After that, it will sputter to a halt ... leaving a mess of white powder and maybe a fire still in progress.
There's a better solution: the Element Fire Extinguisher.
We offer two versions: a 50-second discharge, and 100-second discharge. Either is suitable for your Airstream, your truck, boat, and home.
Dimensions & specifications:
E50 is 30cm (11.75") long, 3.2cm (1.2") diameter & weighs 275 grams (0.6 lbs), comes with mounting clip.
E100 is 33cm (13") long, 4cm (1.6") in diameter & weighs 360 grams (0.79 lbs). No mounting clip.
Suitable for type A, B, C, and K (cooking oil & grease) fires.