Haws SP829HPS Stainless Steel Drench Showerhead, 20 GPM Flow Sinks & Lavatories The unit measures 11 7 8 inches The unit measures 11 7 8 inches in length by 6 3 8 inches in height by 4 inches in depth and requires a rough opening that is 11 3 8 inches in length by 5 1 8 inches in height by 4 1 8 inches in depth 16 Gallon Capacity This new hydrodynamic design minimizes the strong physical pressure that drives the water to the outer rim making the distribution equal across the entire footprint of the flow Better use of the water flowing through the shower makes it more effective while providing a more comfortable environment by breaking the streams of water into smaller individual droplets