This kind of fuse is most commonly used in the case of domestic wiring and small scale usage. Another name for this type is the KIT-KAT type fuse. The main composition is of a porcelain base which holds the wires.
The fuse element is located inside a carrier that is also made out of porcelain. It is possible for you to remove the fuse carrier without any risk of electrical shock. Normally what happens is that when the fuse blows, you can replace it without having to change the complete thing.
The main metals or alloys used in making fuse wire include lead, tinned copper, aluminum or tin lead alloy.