2 inch Aperture Rotation Stage 7R172-2 allows full 360° coarse rotation by hand. You may lock coarse adjustment. Then fine adjustment could be done over a range of 10° using the micrometer. Angular position is read on 360° graduated scale on the platform, which is marked every 1°. The stage has a central aperture of Ø50.8 mm. For horizontal fastening three corners of the base have clearance holes for M6 screws. Vertical mounting: 2 sides of the base each has two M6 holes spaced by 50 mm. For horizontal fastening three corners of the base have clearance holes for M6 screws.