Evolve Roadrunner II shower head 2.0GPM Ideal balance of coverage and great flow- 2.0 GPM WaterSense Certified Integrated ShowerStart technology lets cold water run out, then restricts the flow of water to a trickle when the water gets Just flip the switch or pull the cord to resume normal flow when you are ready to begin showering Attaches to any shower arm with industry standard 1/2-Inch fittings