Non-detectable underground marking tape provides for easy below ground identification, protection, and warning of associated utility lines. Non-detectable tape should be buried 12" to 18" below the surface. Non-detectable marking tape consists of a 4 mil overall thickness and is formulated to resist degradation. Trinity's heavy-metal free, underground marking tape serves as a durable, high-visible warning device that resist the elements. Non-detectable tape is available in 3", 4" and 6" widths and a variety of APWA color codes and legends.