Benchmark Scientific R3005-E TubeRollers are designed for the gentle, thorough mixing of a variety of containers, including Vacutainers, bottles, test tubes, centrifuge tubes and roller bottles. The 5 roller model operates 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. The R-3005-E's 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, Benchmark R 3005 E TubeRollers are the ideal choice for research, clinical laboratories and doctors' offices.