Randon Orbital Action. The 3970 Random orbit sander is the same as our model 3570 except it is designed for Industrial and Hi-Production applications where high performance sanding and dust containment in conjunction with an external vacuum source is required. With a revolutionary motor design, the 3970 delivers Ultra high speed sanding with legendary Hutchins balance and durability. Designed with a captive pad orbit, the 3970 delivers up to 40% more sanding performance and 50% faster operating speed. The 3970 is Vacuum ready out-of-the box and connects to all major vacuum system systems. Comes with patented built-in pad release.