text: An improvement on vibration, vibratory, and linear screeners, a tumbler screener uses elliptical action which aids in screening of even very fine material. As like panning for gold, the fine particles tend to stay towards the center and the larger go to the outside. It allows for segregation and unloads the screen surface so that it can effectively do its job. With the addition of multiple decks and ball cleaning decks, even difficult products can be screened at high capacity to very fine separations.