MARS refrigerant ID labels are color coded to conform to each particular refrigerant. Each label specifies the type of refrigerant, the chemical name, the UN Number and a space for the name and address of the cylinder owner. These self adhering labels are 4-1/2 in x 3-1/2 in, except for MARS No 79528, Refrigerant Evacuation Certificate, which is 7-1/2 in x 4 1/2 in.