The ECHO Arrow Hunter Plus is a complete line of clamp-on Transit-Time flowmeters for portable, permanent and thermal energy applications. Measuring flow on all metal or plastic pipes of 3/8 to 118 in. in diameter, the flowmeter uses Dual DSP technology to measure flow velocity of 0.03 to 82 ft/sec on clean or dirty liquids. Accuracy is factory calibrated and can handle dirty liquids with 10% solids.