Function: 1 Protect your eyes and observe the sun, dark spots, solar eclipse and planetary passage safely. 2. The film density is 5.0 and fits P/A series telescopes, Datyson 5T0001 / 5T0002 and more. 3 High density coating provides the natural color of neutral white under sunlight. 4 Do not look directly at the sun without the protection of the solar filter. 5 40mm telescope solar filter, high performance must have for safe viewing of the sun. Specifications: Item Type: Solar Filter Material: Birder Film + Plastic Color: Film Diameter: Approx. 40mm / 1.6in Objective Lens Cover Diameter: Approx. 50mm / 2.0in Film Density: 5.0 Weight: Approximately 13.0g / 0.5oz Fitting: Fits P/A Series Datyson 5T0001 / 5T0002 Fits GazerLT70 Fits Fenghuang F70400M / F70300M a> How to use: 1 Use the film toward the sun to see if there is no light leakage. If there is a light leak, it is strictly prohibited to use 2. Once detected, install the film cover on the light inlet to confirm fixation, and measure the light with the eyepiece undamaged, and you can perform the operation without any abnormal light. 3 Please do not move the membrane cover during the observation process.