More from Amazon.com : http://www.amazon.com/gp/product/B0000XMWGM?tag=purrfectcatdi-20 <br /> <br />Orion 8548 Explorer II 7-21mm Zoom Telescope Eyepiece <br /> <br />The Orion Explorer II Zoom eyepiece lets you change magnification power without physically changing eyepieces <br />A twist of the zoom eyepiece housing changes focal length from 21mm to 7mm providing a variety of viewing magnification powers <br />Eyepiece consists of four elements which are fully coated with anti-reflection coatings for clear contrasty views <br />Exceptionally long 33mm-to-16mm eye relief range allows eyeglass wearers to enjoy the entire view while still wearing their corrective lenses without vignetting <br />The 125 barrel is threaded for use with like-sized Orion eyepiece filters
