The Phoenix Contact Part 1051029:0021 is a Zack marker strip designed for efficient labeling. It consists of 10 sections that are vertically labeled with consecutive numbers from 21 to 30. The marker strip is white in color and has a width of 6 mm. It is ideal for organizing and identifying electrical components in various industrial applications. With its clear and easy-to-read numbering system, this marker strip streamlines the identification process, enhancing overall efficiency and organization in your project.