Because our famous Standard Denk Binoviewer included in this Package has a BIG 26mm clear aperture but the price of this super economy package is EASY to afford. This system is also easy to use because a correcting system that allows focus in several magnifcations with Refractors, Newtonians and SCTs is also included. You'll never have a problem bringing focus to a pair of eyepieces and they will operate at two magnifications in any Refractor or Newtonian and three magnifications in an F/10 SCT including a focal reduction mode.  Click on the photo, read all about it.