Image stabilization (S)|
The Zeiss ClassiC 20x60S and DesignSelection Mono 20x60S feature an image stabilization system - - all-time first for Zeiss. This system compensates for hand tremor, thus allowing viewing at 20x magnification without the need for a tripod.
Interpupillary distance (PD)
PD is the distance between the midpoints of the eye pupils of the observer.
It is important to carefully set the PD on the binoculars so that you can look directly along the optical axis, as the residual aberrations of the optics are minimized here.