I have two boxes. One has my power panel and battery and fuel/fuel pump and starter and little else except a prop wrench. That's my flight line box. In my vehicle I carry a larger tool box with hand tools, glue, spare glow plugs, and a corded spare starter (I use a cordless starter on the line) spare props and anything else I think I might need at the field. I don't plan on any major repairs at the field and I take it home after a crash. I take the small lightweight box to the pits and leave the other in my pickup which isn't far away if I need a prop, glow plug or handtools. I built the small box myself out of plywood. The large one is a regular fishing tackle plastic box. There are several field boxes and box kits froom the major suppliers.