A vibratory conveyor, whether Vibra-Glide, Ajax shaker, or eccentric-powered, equipped with the right screen does an excellent job of size grading objects. Perforated screens separate objects based on maximum dimension, while rod or bar screens separate based on minimum dimension. Length grading is usually accomplished by first aligning products and then passing them over a specific sized gap. For some products a rotary reel or roller grader can be used instead of a vibratory conveyor.