Moving from a cooler temperature to warmer environment can cause condensation in a camera and lens. To prevent the condensation and keep the ideal humidity in a camera body and lens, the Dri+Cap has a color indicating silica gel in a special packet that does not shed dust particles.
The packet is placed in a chamber in the rear of each Dri+Cap. The chamber has an O ring to keep the cap sealed and not allow the packet to absorb moisture when the cap is not on the item. When attached, the Dri+Cap has another O ring to keep moisture out of the camera body or lens and to allow the packet to absorb whatever moisture the lens or body has been exposed to.