The following specifications will help determine if the Marsh Multi-Mag L Series is suited for your specific flow measurement application. Zero Stability: ±0.03 ft/s (±.009 m/s) Linearity: 0.3% of range Repeatability: 0.20% of range Accuracy: ±1% of reading from 0.3 to +20 ft/s + zero stability Has reverse flow indication    (Other models available with highly accurate reverse    flow capabilities) Range: (nominal pipe sizes)