FAP

The FAP end plates are normally used at the end of a row of terminals. If different terminals are being used within the same terminal block, then you should insert end plates in order to ensure that the touch-safe protection is maintained.
The outer dimensions of the end plates match the dimensions of the terminal blocks. Coloured end plates are often used to establish a clear visual separation between the different circuits or voltage levels.
In addition, the use of end plates increases the clearance and creepage distances, which in turn influence the voltage ratings. The locking pegs ensure that the end plates can be mounted quickly.