This mass flow controller by Unit Instruments is a reliable and efficient tool for controlling the flow rate of O2 gas. With a port diameter of 1/4 in and a maximum flow rate of 1000 SCCM (1 SLM), this controller is perfect for industrial and laboratory applications. It is a used item but has been well-maintained and is in good working condition. The UFC-1160A model is manufactured in the United States and is suitable for use in hydraulics, pneumatics, pumps, and plumbing. The brand is known for its high-quality instruments and this mass flow controller is no exception. Purchase this item and experience accurate and precise gas flow control.