A perfect optical match with Schmidt-Cassegrains and fast Newtonians. The finest zoom eyepiece available. Graduated scale in 1mm units indicates exact focal length in use. High-eyepoint yields comfortable observing even with eyeglasses. Internal zoom lenses move on the smoothest, most precisely-machined tracks yet developed for zoom optics.
Performance is fully consistent with the finest fixed-focal lenght eyepieces.
Threaded for filters, rubber eyecup. Plossls yield the finest image corrections obtainable from the classical 4-element Plossl design. Focal lengths from 5mm through 25mm are parfocal, so that, at most, only slight refocusing of the image is necessary from eyepiece to eyepiece. Chrome-plated brass barrels are threaded for standard filters. All eyepieces are fitted with fold-down rubber eyecups for comfortable observing.