Specification Brand : Spectrum Telescope BulletPoint : Drives BulletPoint1 : Capture the stunning phases of the total solar eclipse with our premium solar filter, which is specially designed for Capture the stunning phases of the total solar eclipse with our premium solar filter, which is specially designed for telescopes. You can safely view and photograph the sun’s partial and annular phases with our ND5-rated filter that blocks 99.999% of the sunlight. BulletPoint2 : How do I determine the size of filter to order? Spectrum Telescope filters slip over the sky end of the optical tube of the telescope. To get the proper fit, measure the outer diameter by using a caliper, ruler, or tape measure. Measure the widest distance of the telescope end starting from the exterior of the casing, across the center and to the exterior part of the casing of the other side. BulletPoint3 : After you have your measurements, you should order a size larger than what you measured. This is because your measurement is being compared with the solar filter ID (inside diameter). For instance: If you measure 4″ across the optical tube end needs a 4.25” size solar filter. This will make it just a little bigger than the measurement you took. BulletPoint4 : Spectrum Telescope has been manufacturing and selling Solar Filters for 25 years. Our filters have been used by amateur and professional photographers to capture amazing photographs of solar events worldwide. Color : One Color ExternallyAssignedProductIdentifier : 7604642978302 ExternallyAssignedProductIdentifier1 : 0751369820029 ExternallyAssignedProductIdentifier2 : 751369820029 IncludedComponents : Optical Glass, Aluminum ItemName : Glass Telescope Solar Filter by Spectrum Telescope ((2.25" (57mm). Fits Optical Tube Diameter 1 7/8" (48mm) to 2 1/8" (53mm)) ItemPackageDimensions_Height : 1 centimeters ItemPackageDimensions_Length : 1 centimeters ItemPackageDimensions_Width : 1 centimeters ItemPackageQuantity : 1 ItemTypeKeyword : telescope-filters Manufacturer : Spectrum Telescope Material : Glass ModelName : TGLGTQPX ModelNumber : TGLGTQPX NumberOfItems : 1 PartNumber : ST000G PhotoFilterEffectType : Neutral Density ProductDescription : Spectrum Telescope manufactures durable, high quality solar filters that are the safest on the market for viewing the sun. These white light solar filters prevent damage to your equipment or your eyes as you view granulating, sun spots, or a solar eclipse. They fit cameras, small reflectors, spotting scopes, telescopes and view finders as well as binoculars. We have been building and developing safe solar filters for over 25 years. Our solar filters are made premium Solar Glass, which is a high-quality glass that has a reflective coating on both sides to enhance the contrast and clarity of the sun’s image. The glass is mounted into an aluminum outer cell, which is durable and lightweight. Our solar filter is easy to use and fits most telescopes. it's design that allows you to attach it to the objective lens of your telescope securely. The filter is secured and centered to the telescope with nylon thumb screw(s) and felt tabs, which prevent any damage or scratches to your telescope. With our premium solar filter, you can enjoy the sun’s beauty and power without any risk or hassle. ProductSiteLaunchDate : 2016-09-03T19:34:34.894Z Size : 2.2Nm Kit Style : (2.25" (57mm). Fits Optical Tube Diameter 1 7/8" (48mm) to 2 1/8" (53mm) SupplierDeclaredDgHzRegulation : not_applicable UnitCount : 1 UnspscCode : 41111700 WarrantyDescription : 30 day Manufacturer warranty WaterResistanceLevel : waterproof