• New Ultra black design, fully multi-coated
• 15mm focal length, 2" fitting diameter
• This super ultra wide angle eyepiece has 80 degree field of view
• Standard female thread to fit a filter etc at the rear end
• The inside of the adapter is fully threaded to minimize reflections
• Coma-free View out of 72% of the field radius
• Great Contrast and Color Correction
• Packed in a protective plastic case

Specifications:

• Structure of optical system: 80 ° ultra wide series eyepiece
• Focal length 15mm/20mm/30mm
• Interface size: 2 '' (50.8mm)
• Angle of view: super wide 80 degrees
• Optical design:
• 15mm: 4 groups of 6 elements
• 20mm: 5 groups of 7 elements
• 30mm: 4 groups of 5 elements
• Eye relief: ≤ 20mm
• Coating: Full coating broadband green film
• Standard internal threads for rear mounted filters, etc
• Threads for filters and Barrow lenses: 2 inches
• The adapter is fully threaded internally to minimize reflection
• Material: glass+metal
• Color: super black design