Features: Real-time "Flow Rate" and "Accumulated Volume" display. Flow + time-based. Monitors up to 6 filters simultaneously. Bar display for residual filter life. Independent filter life value setting. Built-in audio alarm alerts user for filter change. Monitors used time up to 99 hours. Quick and easy 2-step installation, separate plate included for quick mounting. 1/4" QC model able to measure volume when flow rate is between 0.1-1 GPM 3/8" QC model able to measure volume when flow rate is between 0.2-2 GPM FDA-approved materials guarantee user safety. Built-in memory chip to secure consumption information. Auto shut-off. +/- 5% Accuracy Number of Filter Monitored: Up to 6 filters Power: Two 1.5V AAA Batteries Expected Battery Life: 3 years Dimensions: 122mm x 34mm Weight: 60g