It is a kickstarter for your BBQ.

This little guy works pretty good if you are impatient getting your charcoal up to cooking temp. Adding some air will make the fire burn hotter and faster. Also handy for a smoker when you add fuel and need to get the cooker back up to speed. Be careful when you already have food on the grill as if you blow hard close to the charcoal you will blow ash onto your food. There is a little learning curve involved but this product does work well. I have used it for a year now and, probably 20+ fires and haven’t changed batteries yet. (although you really only use it for a few minutes per fire). Also be careful with hardwood lump charcoal like mesquite as it will spark a lot if you blow too hard.
OK, my FiAir worked really well for about two years plus. Then I let it get a little wet in the rain. Darn, something critical inside got rusted. I missed this little blower so much I ordered another one immediately. It works great but don’t get it wet! Great machine. I use it mostly when I am in a hurry to get my charcoal fire in my Weber kettle going or my offset smoker to heat up things when I add more charcoal. A very good tool, but keep it dry.