The features offered by this showerhead include a maximum flow rate of 1.6 gallons per minute, a pressure compensating flow regulator (insuring consistent performance from 40 to 80 psi of water pressure), a non-aerated rain style spray pattern to deliver better water coverage and showering comfort, along with reduced diameter spray nozzles to improve the shower feel.The most unique feature, however, is Evolve's ShowerStart technology. When the shower is initially turned on the ShowerStart device monitors the water temperature. When the water temperature reaches bathing temperature, (95° F / 35° C), the conservation mode is activated and the device “triggers a trickle”. This prevents your hot water from running down the drain before you're ready to get in the shower. Not only have you eliminated the water and energy waste, but the sound of the trickle tells you that your shower’s ready. The water for your shower is now warm and waiting instead of warm and wasted. Turn the valve on the showerhead, the water flow will resume, and enjoy your shower. After each shower the ShowerStart device will automatically reset. This showerhead has solid brass fitting with an ABS body, a head diameter of 3.25", and will attach to any shower arm with industry standard 1/2“fittings. Specifications: • Manufacturer Warranty: 3 Years Additional Information: Manufacturer Specification Sheet (pdf) Important Note: The ShowerStart device on this showerhead is not suitable for use with tankless water heaters.