3M EMS Near Surface Marker is specially designed for marking underground telephone lines accurately. It comes in a cylindrical shape, allowing for easy installation in asphalt or concrete, without extensive digging. This marker offers positive identification of facilities.3M EMS Near Surface Marker provides an effective way of marking underground facility lines during construction or maintenance applications. It withstands a temperature range of 4 to 122 °F ( 20 to 50 °C). This waterproof near surface marker has a long lasting passive antenna, encased in a waterproof shell to identify underground facilities with its exact location, even in congested areas. When mapping new and legacy assets, the pre programmed unique serial number integrates with back office mapping and GIS systems.