Same Magnifications for both TSN-880 and TSN-770 Series features New mount design and improved field of view at lower magnification. The Aspheric 6 group, 9 element lens design gives a very flat field throughout the zoom range and a Long eye relief for ease of viewing. Waterproof and nitrogen purged to prevent the lens from fogging; eyepiece converters allow the use of eyepieces from other spotting scope series.

The eyepieces have a locking system, to prevent loss.