The material of the Self Clean Device is cold roll steel, it contains fan, pre-filter and secondary or HEPA filter. The Self Clean Device could adjust the wind speed according to the actual circumstance. The purification rank at air's exit can reach hundred rank and at worktable could reach thousand rank. This device has movable wheels and adjustable jack, so we could fix up at a special place. It's very agility and convenient. Because it takes a speed adjustable system, we can keep a good purification state at a part of area.