The Compact Series OMA Oxygen Flowmeter is made especially for medical applications and manually controlling flow from oxygen generators. Flow levels are kept stable by precision valve and knob adjustment. The low cost flowmeter is made from durable clear acrylic plastic. They easy-to-read scale is hot stamped into the acrylic so it will not wear off. The ball float is highly visible against the light blue background. Readings are repeatable within +/- 4% full scale accuracy.