The PR-550 Broadband Polarization Rotator provides precise control of the polarization orientation of a laser beam. Unlike λ/2 wave plates, this rotator provides broadband performance over a 400 to 700 nm wavelength range. It features a large 10 mm aperture, wavefront distortion below λ/2, and less than 10 arc sec beam deviation. Polarization rotators are fabricated from two N-BK7 Fresnel Rhombs, which are optically contacted, avoiding the use of cement which would limit power handling capability. The entrance and exit faces are broadband antireflection coated for greater than 98% transmission. The polarization angle control provided by these rotators is required for a variety of applications including ellipsometry, polarimetry, scattering measurements, and component testing. A graduated scale on the rotator housing makes it easy to set and read the rotation angle with 10 arc min resolution. Our polarization rotators are designed to mount conveniently on lasers using a standard 1-32 threaded mounting bezel. A slotted riser base is available to set the optical axis at 50.8 mm and mates with English and Metric optical tables and components.