50-Pack Humidity Indicator Cards 10%–60% Six-Dot Test Cards
50-Pack Humidity Indicator Cards 10%–60% Six-Dot Test Cards
50-Pack Humidity Indicator Cards — Six-Point, 10%–60% Range
Keep your moisture-sensitive items protected with these easy-to-read Humidity Indicator Cards. Designed for use inside sealed containers, storage bags, equipment cases, and packaging, these six-dot indicator cards give you an instant visual reading of relative humidity levels — no batteries, no apps, no guesswork.
Simply place a card inside any closed container. Each of the six colour-sensitive dots responds to a specific humidity level (10%, 20%, 30%, 40%, 50%, and 60%). Dots turn pink when humidity reaches or exceeds that threshold and return to blue when conditions are dry again. At a glance, you always know whether your storage environment is within a safe range.
Made in Mainland China.
Key Features
- 50 cards per pack — great value for ongoing monitoring needs
- Six humidity checkpoints: 10%, 20%, 30%, 40%, 50%, and 60% RH
- Instant colour-change indicator — blue = dry, pink = moisture detected
- Compact size: 10.5 × 4 cm (4.13 × 1.57 in) — fits most containers and packaging
- Laminated cardboard construction — durable and easy to handle
- Reusable: dots revert to blue as humidity drops
- 100% brand new and high quality
Specifications
| Material | Laminated Cardboard |
| Size | 10.5 × 4 cm / 4.13 × 1.57 in |
| Colour | White card with blue/pink indicator dots |
| Range | 10% – 60% Relative Humidity (6 checkpoints) |
| Quantity | 50 PCS per pack |
| Country of Origin | Mainland China |
Common Uses
- Electronics and camera equipment storage cases
- Ammunition and firearm storage containers
- Food, tea, and herb airtight containers
- Pharmaceutical and vitamin storage
- Collectibles, documents, and archival packaging
- Desiccant/silica gel monitoring — know when to replace your packets
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Frequently Asked Questions
Q: How do these humidity indicator cards work?
A: Each card contains six colour-reactive dots calibrated at 10%, 20%, 30%, 40%, 50%, and 60% relative humidity. When the moisture level in a closed container reaches a dot's threshold, that dot changes from blue to pink. As humidity decreases, the dots revert to blue, making the cards reusable over time.
Q: Can I use these humidity indicator cards with silica gel desiccant packets?
A: Absolutely. These cards are ideal companions for silica gel packets. Place a card alongside your desiccant inside a sealed container — when you see dots turning pink, it signals that your desiccant packets may need refreshing or replacing, helping you maintain optimal dry storage conditions.
Q: Are the cards reusable, and how long do they last?
A: Yes, the cards are reusable. The indicator dots cycle between blue (dry) and pink (humid) as conditions change. Longevity depends on exposure frequency and environmental extremes, but cards kept inside sealed containers with controlled conditions typically remain effective for extended use. Avoid prolonged direct exposure to very high humidity, which can saturate the indicators over time.
Q: What is included in one purchase?
A: Each order includes 50 individual humidity indicator cards (10.5 × 4 cm each), ready to place inside your storage containers or packaging.
Production & Packaging Notice
To maintain high stock availability and fast shipping times, our items are sourced from multiple verified manufacturing facilities. While the core quality, materials, and product specifications remain identical, you may notice slight variations in the packaging design, manufacturing origin, or the wording of the printed instructions.