... a moisture-sensitive chemical is impregnated such that it will change color when the indicated relative humidity is exceeded. This item is ... Indicator Card-(with cobalt)1,Lead-free ROHs compliant2,reversible color change,3,quick delivery within 24 hours4, OEM allowed5, cocl2, coblat ... %-30%, 20%-30%-40%, 30%-40%-50%, 40%-60%-80%.......four dots: 10%-40%, 20%-50%, 30%-60%.....six dots: 10 ...