Tank Only, No Motor, Pre-Unit-Filter Tank. Dirty air goes into the non-centered intake on top of the tank. As it enters the tank it creates a cyclonic cleaning action causing 96% of the debris to fall down to the bottom. The air is then moved out of the tank through the center hole on top where it heads to the actual motorized vacuum unit. Size: 31" tall, 14" wide, and holds 7 gallons.