ASI TubeRollers are designed for the gentle, throrough mixing of a variety of containers, including Vacutainers™, bottles, test tubes, centrifuge tubes and roller botles. Both models (5 roller and 10 roller) operate at a constant 38rpm, chosen as the optimum speed for the broadest range of mixing requirements. As the roller mechanism rotates through each complete revolution, the right side of each roller is gently elevated about 0.5 in (13mm) and returns to the horizontal starting position. This additional, gentle up/down motion provides a "wave" effect and guarantees that the entire sample is subjected to complete, thorough mixing, end to end. This built in tilt feature provides a level of homogeneous mixing uniformity that can not be matched by any stationary roller apparatus. From blood collection tubes to roller bottles, ASI laboratory test tube rollers are the ideal choice for research, clinical laboratories and doctors' offices.