Provides an accurate, convenient, long-lasting method for marking underground assets. Easily installed in asphalt, concrete or rock without extensive digging or drilling. Composed of polyethylene shells that are impervious to minerals, chemicals, and temperature extremes typically found underground. All markers are color-coded to APWA standards for visual reference, while each utility has its own frequency. Up to 100 characters can be imprinted on each marker and can be programmed to include customer specific information, such as: facility data, type of application, material type, size, placement date, etc.