UNICO Phase Annulus Slider for use w/ 10x & 40x Plan Phase Set for G500 Series Microscope. This UNICO Annulus is made to last thanks to extremely durable materials and construction. The Unico Phase Annulus G500 Microscope Sliders are an amazing addition to the UNICO line of Microscope Equipment. Specifications for UNICO G500 Microscope Slider Phase Annuls: For: G500 Series Microscopes Type: Phase Annulus Features of Unico Microscope Phase Annulus for G500 - Sliding: Durable Easy to use Designed for the G500 Microscope line Package Contents: Unico G500 Microscope Phase Slider Annulus G500-8031-1: Unico Phase Annulus Slider - 10x & 40x Plan Phase Set G500 Microscope