Unique humidity card indicates both the current humidity and the maximum humidity attained. Easy-to-read cards are ideal for use with bottles, chemicals, plastic bags, electronics, desiccators, and storage containers. Easily monitor humidity levels in shipments, optics, and packaging. Dual ranges are Current and Maximum. Current range is 0 to 100% relative humidity. Color changes from blue to lavender in increments of 10% RH. Reversible indicator changes color as the humidity increases and decreases. Readable to an accuracy of ±5% RH at 75°F (24°C).