This type of quality control equipment searches for items that are inconsistent with a product. The image comparison looks for anything that is different or abnormal as it goes through the x-ray detector. If it finds something, it will reject the product. X-ray detectors find contaminants such as glass, metal and other items in products. In addition to detecting contaminants, some X-ray detectors can also check the closure, seal and fill level, as well as find damaged packaging, removing any products that do not meet the requirements. They are usually used to inspect finished or packaged products. X-ray detectors help avoid recalls, as they detect problems before items are distributed.