OMAX X-Y Mechanical Stage for Stereo Microscopes Stage size (excluding the knob): 7-1/8inch x 6-1/8inch x 1-1/16inch (180mm x 155mm x 27mm) Stroke : 3inch x 2-3/16inch (75mm x 56mm) Accuracy of X-Y movement measure: 0.1mm Light pathway hole: D37mm; Diameter of base fitting ring: D95mm 1-year warranty against manufacturing defects