The 8500-SH has a flow-controlled weir with adjustable flow rate capabilities. The skimmer will pull oil and water into the skimmer sump. The water is discharge out the bottom of the skimmer sump. Oil accumulates on the surface inside the skimmer. When the oil has thickened on the surface in the skimmer sump. A pump will off load just 100% oil with no water*. The Smart Skimmer has programmable functions and use a PLC type controller. The skimmer can be programed to start and stop at regular interval and if no oil is recovered it will reset. The skimmer can be set up for fully automatic operation or can be “dumbed” down and be manually operated.