The PHOENIX CONTACT part 1050017:0001 is a connector accessory known as the Zack Marker Strip. This strip is designed to be used with connectors, and it features a straight design in a clean white color. The Zack Marker Strip allows for easy labeling and identification of connections, ensuring efficient and organized wiring within your electrical system. With its high-quality construction and user-friendly design, this marker strip is a must-have accessory for any professional or DIY electrical project.