This neutral density filter transmits light uniformly across the visual spectrum. It serves as an excellent filter to reduce glare and improve viewing comfort when observing the Moon with larger telescopes. This filter may also be employed in the splitting of close double stars if one of the binary pairs significantly exceeds the other in brightness. The special-purpose filter features a 13% total light transmission. Threaded for and compatible with all Meade Series 4000 and Series 5000 eyepieces. Product carries a full one year Meade factory limited warranty.