Power cable marker posts, constructed from durable PVC/glass fiber reinforced plastic, are designed for identifying underground optical cables, gas pipes, water supply lines, and establishing boundary markers. Mark utility service lines above the ground with bright, bold colored stakes and labels. Need more details or have questions about this product? Marking Stakes - Caution Buried Fiber Optic Cable from Emedco - A wide variety of Marking Stakes - Caution Buried Fiber. Browse our selection of underground buried cable marker posts. Several styles to choose from including hybrid flat rail marker posts, dome marker posts, triview marker posts, test station marker posts, pedestal marker posts and more.