When you wait for dark before going out to or take a break after , or wait for the weather to improve during . A dust-proof, dew-proof and waterproof hood is very useful. When you are observing the sun, the main mirror can be shielded to reduce the air turbulence caused by the temperature rise in the lens barrel caused by the sun's irradiation. It can also block the sunlight in the eyepiece to improve the visual effect of sun observation. It is usually placed and used as a dustproof. The product uses double-sided silver-plated thick fabric, which has good heat insulation and water resistance. Shading, stray light adaptation rate is extremely low. Very practical and easy to use. Highly recommended. Type: Telescope dust cover Colour:silver Material:Polyester Size:100x75cm Package Contents: 1 x Telescope dust cover(Without binoculars) Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.