Use of Refrigerant Identification Markers eliminates the confusion and problems caused by charging a refrigeration system with the wrong refrigerant. Preprinted with the refrigerant number, these labels provide clear and professional identification replacing magic marker/masking tape scrawls. Available from stock in colors that conform to American Refrigeration Institute (ARI) Guideline N, these industrial grade indoor/outdoor self-sticking labels come in two sizes for application around or adjacent to the system charge points.