The Nikon is a 20X for the RAII/A and has a 60' AFOV. I estimate it to be around 15-16mm compared with other eyepieces. It is fully multi-coated and is very sharp w/box and caps. Has good eye relief and a fold down rubber eyecup - $60.
The Ultima is a 27mm and has the same features, but no box and cap -$30. Both have threaded barrels. Selling because I'm replacing with a zoom. Buy both for $75 (the Nikon alone is worth that).