The federal government sets rules limiting how much water showerheads can use, and this bill changes how "showerhead" is legally defined for those rules. Under the new definition, based on standards from a mechanical engineers' professional group, showerheads with multiple sprayers could each be counted separately rather than treated as one combined unit — which matters because current water-efficiency limits apply per showerhead, so this affects how much total water flow is allowed. The Department of Energy, which writes and enforces these appliance efficiency rules, would be required to update its regulations to match this new definition. In practical terms, this could allow for higher water pressure or flow in showers, particularly ones with multiple heads, than the current rules permit.