The Meade 07531 Series 4000 ND96 1.25-Inch Moon Filter for Series 4000 and 5000 Eyepieces helps to enhance the experience of viewing the moon with 13-percent transmission. This neutral density filter transmits light across the entire visual spectrum and acts as a filter to get rid of glare and irradiation. Telescopes with apertures of 4-inches and larger are ideal for this item. It can also divide nearby double stars when the brightness levels don?t match. The Meade 07531 Series 4000 ND96 1.25-Inch Moon Filter for Series 4000 and 5000 Eyepieces comes with a 1-year limited warranty. Meade has everything you need to capture the night sky for experienced star-shooters, serious researchers and beginners alike. Serious astronomers for years have flocked to Meade telescopes for their quality optical systems and patented technology. Consumers know that "Meade Optics Inside" means that what they see through our telescopes will be views that are detailed, crisp and full of contrast. Look through a Meade this evening and see what you've been missing.