... main engine of filter, controlling & sucking pipe system 2.Color:blue/gray 3.Length:2-5m 3.Dia.:15 ... SystemLoobo Central Extraction/Purifying System consists of fan, main engine of filter, controlling system, sucking pipe system, accessories, sucking ... the detailed environment and etc. Controlling System: According to the system requirements.Vent Pipe System: Available for carbon steel pipe, ...