Best Value Vacs Orthrus MK-V Bi-Directional Closed Loop ExtractorOrthrus MK V Bi Directional Closed Loop Extractor The 1 lb MK V Bi Directional closed loop increases efficiency by utilizing both a bottom and top solvent input. By using a bottom flood on the first wash, you ensure all material has seen solvent. This method prevents channeling through the material. Finish the run with a top flood input to ensure all residuals have been washed from the material. Oil bearing solvent is collected in the collection base