Plössl is a 4 optics element that offers an excellent image quality and an apparent field of view around 50°, it's ideal for all observing targets.

Barrel size. Eyepieces come in several different barrel diameters, .965", 1,25" and 2". Most telescopes are designed for the 1,25". The 2" is used for large telescope and offers increased field of view and brighter images.