The MACH 10 Meter (Ultrasonic)

How it works:  

• No Moving Parts: This is a "solid-state" meter.  It doesn't use a disc or gears.
• Sound Wave Precision: It sends ultrasonic sound waves through the water stream.  By measuring how fast those sound waves travel, the meter calculates your water usage with extreme precision--even catching tiny drips that mechanical meters might miss.
• Digital Display: This model features an LCD screen that provides high-resolution data at a glance.