Visi-1 processor provides two rates of flow controlOur Visi-1 Single SPE Tube Processor provides precise flow control through a single 1mL, 3mL, or 6mL SPE tube.There is no faster, more convenient, or more reliable method for processing one or a few samples.Simply fill the SPE tube with the appropriate solution, attach it to the Visi-1 processor, and rotate the knurled knob clockwise. The solution will pass through the tube in a slow, uniform rate, consistent with the most reproducible results for SPE. Use the plunger to expel the last drop of solvent from the tip of the tube. Remove the tube from the processor, introduce the next solution, and repeat the process.