The cigarette filler is a manual tool with which one can fill empty filter cigarettes with tobacco. It is an elongated (approx. 10 cm long) metal cylinder (approx. 1 cm in diameter) with an extendable tube that can be opened and filled with tobacco. Once filled it is closed and an empty cigarette case is slid over it.
When the tube is pushed back into the cylinder - where there is a plate that acts as a tamper at the bottom end - the tobacco ends up in the cigarette case.
More modern models are made of plastic. [MOT]