Self-Adhesive Medical Gas Markers comply with the NFPA 99 Health Care Facilities Code and CGA C-9 Standard Color Marking of Compressed Gas Containers for Medical Use. Self-Adhesive Medical Gas Markers are made from durable outdoor grade vinyl and aggressive acrylic adhesive for pipes ranging from 3/4" through 7-7/8" in diameter. Your Self-Adhesive medical gas pipe markers ensure adhesion to a variety of surfaces. Clean and dry surfaces are required for installation. EZ medical gas pipe markers comply with ANSI & ASME A13.1 standards if used in conjunction with arrows sold separately.