A rectangular collimator reduces the amount of radiation a patient is exposed to during dental intraoral x-ray procedures by reducing scatter radiation and focusing the radiaton beam into the same rectangular shape as the sensor or film being used. By decreasing scatter radiation, rectangular collimators also improve image quality. These devices should easily connect to the cone of your x-ray generator and should be NCRP compliant. The rectangular shape of these collimators does a better job at reducing patient radiation exposure than round collimation systems, so if your practice is still using round collimators, be sure to invest in a rectangular collimator.