Intended for use with with longer focal ratio telescopes and eyepieces of narrow to moderately wide apparent fields of view
Free light transmission: 22.5 mm lens aperture; Can be used with additional spacers which is available separately to achieve further focal reduction
Mounting threads: 1.25 inch filter thread; 28.5x0.75 MM on both sides: Threads into eyepieces; camera adapters and other accessories with standard 1.25 inch threads; And can be stacked with additional 1.25 inch threaded accessories
Seamless Magnification Control: A simple twist of the zoom housing adjusts focal length from 8mm-24mm; Ideal for planetary clusters, lunar details, and deep-sky nebulae observation
Extended Eye Relief for Eyeglass Users: 15 to 18 millimeter eye relief; The foldable rubber eye cups also eliminate any stray light; Whether you wear eyeglasses or not; you are guaranteed a good field of view at a comfortable viewing distance