Eyepieces Our Eyepieces are available in two focal lenghts 21mm and 14mm. Why do we make only two focal lenghts of eyepieces? Becuase when using our Power Switch Star Diagonals, all that you will need are two great eyepieces. With our Power switch Star Diagonals, each focal length operates at 3 different magnifcations! They are the best that we can make.
