Dk 021:2015 – 31220000-4 – Elements Of Electrical Circuits (Null Bus With 12 Holes, Pin Bus Three-Phase 63 A, Distribution Box Overhead 100*100Mm, Mounting Box D=68Mm, Socket Double Built-In, Block Of Sockets For 4 Modules Overhead, Terminal Block Separable 2.5 Mm – 31220000-4)