TeleVue 11mm Nagler Type 6

The 11mm Nagler Type 6 slots in perfectly between the 13mm and 9mm Type 6s and makes a perfect companion to the 7mm.
  

The 7-element, Nagler Type 6 design is based on the original patented Nagler design. This new 7-element design update for the short focal length Nagler deserves its own designation. Using different exotic materials, coating processes and design ingenuity, Al has massaged more eye-relief, contrast, and true field of view into the shorter focal length Naglers, while maintaining the absolute sharpness of the originals. Eye-relief is 12mm on each model, and all are sized about the same as the original 7mm! Weight about 0.4 to 0.5 lbs.
  

Why Are There 3 Types of Naglers?
  

To achieve the full magnification range over 82° apparent field of view requires two types: Nagler Type-5 with focal lengths of 31, 26, 20, 16mm and Nagler Type-6 with focal lengths of 13, 11, 9, 7, 5, 3.5, 2.5mm.
  

The Type-5 permits the largest true field possible (31mm has 42mm field stop), while the shorter focal length Type-6 models are parfocal, with similiar size and weight and all with a comfortable 12mm eye relief.
  

The Type-4 models feature about 18mm of eye relief and with the "instajust" eyeguard are best for eyeglass wearers or Dioptrx users in their 22, 17, 12mm focal length range.