[6291]90FL Basic OTA Set Part # 6291 Description 90FL Basic OTA Set Aperture 90mm Fluorite Focal length 500mm F-ratio 5.6 Lens configuration 2 elements in 2 groups Coating Fully multi-coated Physical length 440mm Tube diameter 80mm Weight 2.0kg Filter 82mm (front cap) Parts included 2591, 7101, 77491, 7790, 7835, 7508, 7509 & 7000 Notes