Focal Lenght 17 mm.

Eyepiece with a seat is 1.25" and the field of view of 45° for telescopes of all systems represent the classic symmetric four-lenses system.

Eyepieces are well corrected from aberrations within the angular field of view. 

All lens surfaces have multi-layer coating. 

Eyepieces have threaded fit under standard filters and are fitted with rubber eyecups.

Multi-layer coating reduces light reflection to 0.8% in the spectral region 440-680 Nm.