UNICO Darkfield Slider for use w/ 4x to 40x Power Objectives for G500 Series Microscope. This Unico Objective Lens Slider is built using top-of-the-line materials and construction to offer you a long lasting item. The Unico Darkfield Slider for G500 Microscope 4-40x Objective Lenses is a high quality addition to the UNICO line of Microscope Components. Specifications for UNICO G500 Microscope Objective Lens Darkfield Sliders: For: G500 Series Microscopes Type: Darkfield Sliders Features of Unico Microscope 40x Objective Lens Darkfield Slider for G500: Durable Easy to use Designed for the G500 Microscope line Package Contents: Unico G500 Microscope Darkfield Slider for Objectives Powers 4-40x G500-8041 G500-8041: Unico Darkfield Slider - Power Objectives 4x - 40x G500 Microscopes