Besides doubling the power of any eyepiece, these premium-quality barlows feature 3-element, fully multi-coated lens designs that render exquisite images without introducing additional chromatic aberration. Images appear sharper and more color-correct than with standard, achromatic barlows. They're especially good for high-power lunar and planetary observing and for boosting magnification in short-focal-length telescopes. Barrels are not threaded for filters.

Dude!