Product DescriptionSwanson Non-Detectable Underground Warning Tape aids in preventing damage to underground utility lines during excavation. Following code parameters simply bury this tape above electrical lines gas pipes communication cables and other utility installations to warn workers of their location prior to digging. Resistant to underground elements this heavy metal-free co-extruded polyethylene tape serves as a proximity warning device that maintains its original color and visibility over time.From the ManufacturerSwanson Non-Detectable Underground Warning Tape prevents damage to underground utility lines during excavation. Following code parameters bury this tape above electrical lines gas pipes communication cables and other utility installations. Resistant to underground elements this heavy metal-free co-extruded polyethylene tape serves as a highly visible proximity warning device that will not turn black over time.