In commercial aviation, the term combi refers to versions of various aircraft that can be use for either passenger, as an airliner would, or cargo duties, as a freighter would, and often have a partition in the cabin to allow both uses at once. Combi aircraft typically feature an oversized cargo door, as well as tracks on the cabin floor to allow the seats to be added or removed quickly. Typically, configured for both passenger and cargo duty, the passenger compartment is pressurized to a higher pressure, to prevent fumes from cargo entering the passenger area.