Double the power of any 1.25" telescope eyepiece with the Orion Shorty Barlow Lens</br>A great way to essentially double the number of telescope eyepieces in your collection without having to buy twice as many eyepieces!</br>Very compact - just 3 inch long (half the length of a standard Barlow lens) - easy to stash in your accessory case</br>Doublet lens system is multi-coated for excellent transmission and the internal housing is baffled to eliminate unwanted reflections and increase contrast</br>Threaded for use with 1.25 inch Orion telescope eyepiece filters</br></br>Product Description</br></br>Give your telescope eyepieces a 2x power boost! The Orion Shorty 1.25 inch 2x Barlow Lens doubles the power of any 1.25 inch telescope eyepiece it's used with. For about the price of a single eyepiece or less the practical Shorty 2x Barlow effectively doubles the number of telescope eyepieces at your disposal. The Orion Shorty 2x Barlow Lens doubles the magnifying power of any 1.25 inch eyepiece essentially dividing the eyepiece's focal length by a factor of 2. For example: using a 25mm eyepiece in the Shorty 2x Barlow provides the same magnification a 12.5mm eyepiece would normally exhibit (25 / 2 = 12.5). Using this simple formula?? you can easily determine how each of your 1.25 inch telescope eyepieces will perform when inserted in the Shorty 2x Barlow Lens. A 20mm ocular will behave like a 10mm eyepiece; a 6mm eyepiece will provide the magnification of a 3mm eyepiece?? and so on. Using the Orion Shorty 1.25 inch 2x Barlow Lens is easy. Simply insert the Shorty 2x Barlow into your telescope's focuser or diagonal?? and then insert any 1.25 inch eyepiece into the Orion Shorty?? gently securing it in place with the two thumbscrews