The electronic part 561-00301 is a Wire Labels & Markers Clip On Cable Marker 2-2.8 mm international resistor colour code Imprint L1,L2,L3,N,EARTH manufactured by HellermannTyton. This cable marker is designed for use on power and data cables with a 2-2.8 mm thickness. It has built-in resistor colour code printing to ensure the wires are correctly labelled. The printing includes L1,L2,L3,N, and EARTH. The L1, L2, and L3 labels are used to identify the phases of the installation (i.e. for single phase installations the label should be L1, L2 and N. The N label is used to identify the neutral connection and the EARTH label is used to identify the earth connection. This cable marker is designed for quick and easy installation and provides a professional looking finish.