The PHOENIX CONTACT ZB 5 QR:FORTL.ZAHLEN 21-30 marker strip is a crucial component for maintaining organization and clarity in electrical panels and terminal block systems. This marker strip is specifically designed for use with ZB 5 terminal blocks, offering a secure and durable labeling solution. The strip is vertically labeled with consecutive numbers from 21 to 30, making it easy to identify individual circuits and connections. Its white color provides excellent contrast and visibility, ensuring that the markings remain legible even in challenging environments. This marker strip is ideal for industrial automation, control systems, and any application requiring precise and reliable terminal block identification.