Pixco Silica Gel Desiccant Moisture Orange Indicating for Absorb Box Reusable Widely used in precision instruments, leather, shoes, clothing, food, medicines and household appliances. Can be placed in closets, coat or sweater inside the box to prevent mildew, etc. Can be used to protect the camera, lens, microscopes, telescopes, audio and video equipment, records, tapes, video tapes and computer diskettes, etc., in order to prevent mildew. The orange silica gel desiccant will turns to green color when it absobed moisture from the air. You can reuse your used silica gel with Microwave. Heat in microwave just 5-8 minutes (Medium / low power), Color will slowly change back to orange after reactivation.