This advanced five-position turret condenser allows an instant change between contrast techniques for observation of low-contrast or transparent specimens and living cells, or when staining is not desirable. It incorporates phase annulus rings for 10X/20X, 40X and 100X objectives as well as Brightfield and Darkfield positions.The phase annuli are easily centerable with two knurled alignment knobs. The condenser features an iris diaphragm and engraved turret positions for convenient operation.