Leave both hands free for manipulation of 50mL sample tubes Handy polysterene base securely holds a 50mL conical centrifuge tube in place, freeing hands for tasks such as pipetting and adjustment of instrumentation Allow better control of procedures involving measurement, analysis and modification Grip Style securely holds the tube in the base and moves with the tube when it is lifted from the benchtop; remove tubes by holding the base and pulling out tube Non-Grip Style allows the tube to be lifted freely from the base