The SJ25.4 is a compact, kinematic mirror mount designed for use with the X26 Steel Four-Sided Optical Rail System. The mount provides accurate positioning of 1 in. (25.4 mm) diameter mirrors or beamsplitters with a thickness of 0.157 to 0.315 in. (4 to 8 mm). A large clear aperture at 45° is useful for beamsplitting applications.Precision adjustment screws provide ±1° tip/tilt for the alignment of mirrors, and have a hex head for tamper-proof Allen wrench adjustment. The addition of the optional TSJ Rotating Base allows coarse 360° positioning of the mount.Mounting SJ25.4 on one side gives an optical axis height at 32.5 mm for direct mounting on CN26 Carriers. Mounting on the other side gives an optical axis height of 19.5 mm, for use with UMR5 Series Linear Stages or the TSJ Rotating Base. Both yield a 40 mm beam height above the rail surface.