These Plössl eyepieces have all the features that a good Plössl eyepiece must have. They come with a rubber eyecup that prevents the intrusion of stray light from the sides. The blue coating ensures good image contrast. There is a filter thread for the use of filters with a 1.25" thread. Plössl eyepieces do not cause chromatic aberration due to their four-element design. Some very simple telescopes are often offered with three-element or even two-element eyepieces, which can cause significant chromatic errors and loss of contrast. This Plössl is a good and affordable replacement for those eyepieces. Plössl eyepieces are very versatile; they are suitable for all types of astronomical observation as well as for terrestrial observation. With full coating on every glass-air surface, the eyepieces provide good contrast.