Franke FM100 StillPure Bluetooth Undersink Filtration Filter Water Usage Monitor (Compatible with Android and iOS), 1" x 4.5", Red Monitors ACTUAL water usage and provides statistics via smart phone app (available for Android and iOS) Automated notification based on usage data when it's time to replace filters Installs in-line with any water filtration system utilizing quick connect fasteners Connects to smart phone with Bluetooth connectivity Know plastic bottles saved from landfills, money saved, and conveniently alerts you when it is time to change your filter