Super Plossl 17mm lenses, diameter 31.8mm (1 1/4").

• Lens quality: top quality with 4 elements.
• Design: excellently designed and corrected eyepiece lenses.
• Field of view: 52º, large enough for pleasant observation.
• Multi-coated lenses: with blackened edges for high contrast.
• Error reduction: minimize spherical and chromatic aberration, astigmatism, and distortion.
• Stray light: minimized by foldable rubber extensions.