High-efficiency Poli segmented brake discs, self ventilated. These discs have a spaced segmented friction ring which can be easily disassembled. Segments can freely expand and have a fixed connection to the special steel hub. They are made by special NiCrMo alloyed cast iron with high resistance to thermal stress and wear: this allows a longer life than our competitors. Since the hub is unalterable it does not need to be replaced, hence the wheels must never be dismounted. Long testing carried out by various Railway and Mass Transit Authorities have shown how the mean temperature, on the surface of POLI brake disc, is lower than the one on any other type of disc. Consequently, pad wear is lower. This design is suitable for all kind of application, from Metro to High Speed Train.