Medium series models 3/4" - 2 1/2" available with calibrated scale and needle pointer. Minimum Scale 0-40 L/min Max 0-400 L/min (3/4" - 1 1/4") Max 0-500 L/min (1 1/2" - 2") Max 0-800 L/min (2 1/2") Specify scale range and engineering units as well as: seals, connections and switch configuration at time of order