The ideal solution for night photography in humid weather. Prevents dew from forming on camera lenses and telescopes. Holds chemical hand warmer packets that warm lens enough to prevent dew. (Hand warmers not included.) Tough, weather-resistant nylon outer shell and soft inner fabric to protect lens. Works on camera lenses, telescopes, spotting scopes, and other optics. Attaches easily with Velcro. Can be daisy chained to fit large optical tubes.