Datyson 5P9973 Telescope UHC Blocking Urban Light Pollution 1.25 inch Light Pollution Blocking Filter Feature: 1. Filter out urban light and polluted light, making the field of vision clearer 2. The UHC filter belongs to the broadband filter in the astronomical filter series, which has a significant effect on eliminating harmful urban light 3. Because the filter is an interference filter, different angles and different colors are displayed. It is coated with imported nano-level coating to ensure that the film is resistant to high temperature, corrosion, and not easy to fall off. 4. It adopts the international standard inch thread, which is suitable for all kinds of astronomical telescopes with inch thread standard. Align the thread of the filter with the eyepiece and place the threaded filter into the eyepiece for viewing. 5. The outer packaging design of the filter is simple and beautiful, and the inner lining uses thick shock-absorbing cotton to ensure the safety of the product during transportation and carrying. Parameter: 1. Interface size: 1.25 inches (31.7mm) 2. Thread specification: M28*0.6mm 3. Lens material: optical glass 4. Frame material: aluminum alloy 5. Net weight: 9g 6. Gross weight: 30g Shipping list: Light pollution filter 1 Plastic storage box 1 Packing carton 1