Small gas mass flow meter, selectable flow range 0~20L/min (DN 6mm), 0~100L/min (DN 8mm) and 0~250L/min (DN 12mm). Digital display, easy to read. High sensitivity and good repeatibility, accurate to trace the flow rate. Battery-powered, low power consumption. Favorable price and high reliability, suitable for instantaneous flow rate and flow accumulation of compressed air, oxygen, nitrogen, etc.