1.valve type flowmeter 2.nice looking,light weight 3.durable performance ... mainly made by acrylic glass,widely used for oxygen measuring,control oxygen flow.Featured with nice figure,light weight,unbreakable,long life ... .F10/20/30 glass tube flow meters,LZZ/LZD(-F)metal tube flow meters,organic panel type pure water flow meters,UHC magnetic flap ...