Thorlabs' optical rails are used in constructing 1D, 2D, or 3D optomechanical assemblies and are offered in seven different varieties: dovetail, 25 mm, 34 mm, 50 mm, 2", 66 mm, 75 mm, 3", and 95 mm. Our optical rails are manufactured from aluminum and offer superior parallelism and rigidity. These optical rails are well suited for building long, parallel beam paths, optical enclosures, or large-scale, load-bearing structures.