Min.: 700 rpm. (4,398 rad.min-1) Max.: 1,500 rpm. (9,425 rad.min-1) Description. The Vibratory Disc Mill RS 200 is engineered for size reduction, mixing, grinding of medium-hard, frail or course materials to analytical quality. The Vibratory Disc Mill by Retsch, with a variable speed of 700-1,500min, is designed for construction materials ...