1) Double cylinder, high air flow 2) Oil free, piston type; No air polluted. 3) Double air pressure switch. Product Name: Double ... gauge. 4) Double air pressure switch.Switch 1, low pressure switch, for airbrush purpose.Switch 2, high pressure switch, for other high pressure air tools ... r.p.mAir output per min./liters: 35~40L/minDouble switch: switch 1: Auto stop, start at 3BAR(43psi), stop at 4BAR ...