Pentax premium spotting scopes adhere to the American standard of 1.25" eyepiece thread diameter, facilitating the use of eyepieces from independent manufacturers. That also means, of course, that the wonderful Pentax eyepieces can be used in other telescopes and spotting scopes which accept 1.25" eyepieces.
All of the Pentax eyepieces exhibit an apparent field of view of greater than 50°, which is the generally agreed-upon maximum viewing field that an observer has in their non-peripheral vision. You'll feel like you are surrounded in space with a distortion-free portal to distant scenes at your disposal.
Waterproof & fogproof with minimum eye relief of 18mm
USA Standard 1.25" eyepiece threading diameter
Accepts conventional 1.25" diameter filters for astronomical and terrestrial applications