The brands we carry at High Point Scientific. The manufacturers listed at any given time during your search refinement offer at least one product that matches other search criteria you have already chosen.
Barlow lenses and Focal Extenders increase the effective magnification, or power, of any eyepiece with the same barrel size when they are used together with a telescope. However, not all Barlows increase magnification by the same factor (X). For instance, if you have an eyepiece that achieves 100X power in your telescope, using that same eyepiece (and telescope) with a 2X Barlow will double that magnification (200X). If you choose a 3X Barlow, it will triple the magnification (300X).
Since Barlow lenses, like eyepieces, slide into a focuser or adapter, it is important to match the size of the chrome barrel to the focuser or adapter you plan to use it in. Before you buy, check your telescope focuser's size. If you're lucky enough to have a 2" focuser with a 2" to 1.25" adapter, you can choose either barrel size, although unless you have some 2" eyepieces, you may want to go with the more economical 1.25" Barlow.