... parts, high durability 2,Convenient installation and maintenance and Intelligent Vortex Flow Meter Built in Piezocrystal Simple Structure Long ... Service Life Wide Application KVFN Intelligent Vortex Flow Meter, produced by Chongqing Endurance company ... , RS-485, Hart, Modbus Power Supply: 24VDC / 3.6V Lithium Battery / Double Power Supply (24VDC, 3.6V Lithium Battery) ...