Propane lanterns are more complex in design. A lantern of this type is typically screwed onto the top of a propane bottle. A fuel tube runs upwards from the bottle, then turns downward and is open at the end. The end is capped off with a small bag-shaped piece of loosely-woven fabric called the mantle. The mantle must be burned before its first use. Propane flowing from the fuel tube catches fire, and transfers its heat to the mantle, which incandescess like the filament in a lightbulb. For protection, a cylindrical glass shield called the globe is placed around the mantle. Propane lanterns are very bright, and can easily be used as reading lights.