Series VFA/VFB - Visi-Float® FlowmeterUsed to Indicate or Manually Control Air or Water FlowDwyer Visi–Float® flowmeter bodies are cut and precision machined from solid, clear acrylic plastic blocks. This construction not only produces a handsome finished product, but permits complete visual inspection. As a result, the Dwyer Visi-Float® flowmeters are especially popular for medical and laboratory equipment applications. Series VA - Variable Area Glass Flowmeter65 mm and 150 mm, ±2% FS Accuracy, Interchangeable FlowtubesAccurately measure flow rates of air, water, and other commonly used gases with the Series VA Variable Area Glass Flowmeters. Flowmeters are designed with an easy-to-read universal mm scale and supplied with a correlation chart containing calibration data for air and water. Correlation data for other gases and liquids are available. Permanently fused ceramic scale with vertical locator line reduces parallax and eye fatigue. Thick polycarbonate front shield protects tube from breakage and also serves as a magnifying lens to enhance reading resolution.