McMath Controls Hand-Crank Centrifuges are available for short cone, pear and finger centrifuge tubes. The reliable, durable and rugged construction makes this centrifuge ideal for field use. It has a smooth dual-gear driven system with the gear ratio of 16:1 to assure efficient centrifugal force for sediment and water testing. The design of the gear ratio and throw of the crank produce smooth effortless motion with maximum speed and minimal effort. The crank design provides ample clearance in all directions when the tube shield and samples are in motion.