A must have for lunar observing in telescopes with apertures of 4 inches or larger. A full moon's light through the eyepiece of your telescope can be blinding. A moon filter acts like a pair of sunglasses! Dramatically reducing glare, brightness and lets you observe the lunar surface comfortably. Craters on the lunar surface stand out in better detail and definition. The Meade series 4000 ND96 Moon Filter is 1.25 inch format and manufacturered from crown optical glass. Anti-reflection coatings on both sides and is mounted in a machined aluminum cell. Filter threads into the barrels of nearly all 1.25 inch eyepieces. See the moon the way you should 13% light transmission 0.9 density Dramatically reduces glare View the lunar surface in much greater detail