... RoHS compliant 4.Economical cost, convient use 5.High quality Eco-friendly humidity indicators1, Brief:humidity indicators, HIC, cobalt free humidity ... %-40%, 20%-50%, 30%-60%..... six dots: 10%-60%....... OEM services allowed 4, Application Printed Circuit Board,PCB, LED, SMD LED ... of humidity indicators to a can, 3000pcs to a carton Eco-friendly humidity indicators Eco-friendly humidity indicators