- Aperture : 90mm Fluorite apochromat
- Focal length : 360mm
- F-ratio : 4.0
- Lens configuration : 6 elements in 5 groups
- Coating : Fully multi-coated
- Physical length : 400mm
- Tube diameter : 80mm
- Weight : 1.9kg
- Filter : 82mm (front cap) & 48mm in front of reducer
- Parts included : 2591, 7151, FTF-BORGII, FTF-M57, 7872 & 7352
90FTF4 : 90FL Astrograph FTF Set
