Strong and reliable flow meter, offering the latest technical improvements for a precise measuring of the flow, with +- 5% accuracy. .Chrome plated brass body. Graduated flow tube and cover made of polycarbonate & unbreakable. Adjustable flow by needle valve (knob) with micrometrical regulation. Back pressure compensated. Standard flow 0-15 LPM.Inlet filter made of S.S. wire net. Humidifier bottle made of polycarbonate, transparent and unbreakable. Fully autocalable at 121o C.