Focusing mask is made of metal. It is very lightweight and will not become burden to maintain the balance of the telescope. Simple structure design. The focusing mask can be easily connected to any telescope. It is manufactured with professional technology to ensure the of the product and can work for long time. Features - Material: Metal. - Size: 12.00X12.00X0.20cm/4.72X4.72X0.08 inch. - Focusing mask can bring the best focus for your telescope quickly and easily, excellent and reliable. - Suitable and wonderful for use on all types of telescope, useful and practical for you to use. - The mask with unique design will protect your valued telescope surface, protective and safe. - It is simple in design, but it's practical to use, which will give you fantastic use experience. - Adopts precision production to increase the stable characteristics and high reliability. Package list: 1 x Astronomical Telescope Focusing Mask