The spiral stairs are actually only made up of stairs - meaning the middle pole (spindle) on which the stairs are hung must be ordered separately. In the case of the 1:25 and 1:50 sets, no middle pole is included (it has to be ordered separately). For the 1:100 and 1:200 sets, (exchangeable) middle poles are indeed included. Possible products suitable for use as middle poles include PS strips, ABS tubes, brass tubes or spring steel wire.