The RZ features a 10:1 zoom ratio with built-in variable dual-iris diaphragms and 12 positive click stops through the zoom range. Two perpendicular columns of eight zoom lenses in four groups move in smooth motion controlled by ergonomically sized and positioned zoom knobs. A magnification indicator is conveniently located on the zoom controls. Ergonomic Tilting Binocular Head. Trinocular heads are available. BF/DF stand included. Many different stands are available.