Sky-Watcher’s 2X(ED) Barlow Lens doubles the magnification of any eyepiece placed into it. It also helps to obtain high powers with longer focal length eyepiece for comfort. Your eyepiece fits snugly into the Barlow and is secured with a pressure ring, so there is no scratching from tightening screws against your eyepiece. The ED Barlow lens is compatible with all 2” and 1.25” eyepieces (adapter included) and improves their performances significantly, especially when used on telescopes with short focal length. Though best suited for ED refractors and Newtonian reflectors, this product can be used on any optical tube assembly.