What Mueller Water Products, Inc. told the SEC could break it.

Mueller depends on a small group of waterworks distributors: one customer represented 20% of gross sales in FY2025 (and FY2024) and its two largest distributors together accounted for ~37%, with no long-term contracts; loss or reduced purchasing by either large distributor would materially reduce sales.

“The Company has two significant customers that comprise greater than 10% of gross sales. One customer comprised 20 % of gross sales for each of the fiscal years ended September 30, 2025 and 2024, and 18 % of gross sales for fiscal year ended September 30, 2023.”

Mueller's brass/bronze and iron castings depend on metals (copper, steel, aluminum) and other purchased components whose prices are volatile; it experienced ~3% raw-material inflation in 2025 and anticipates further inflation in 2026, which would pressure margins to the extent it cannot pass costs through to customers.

“We anticipate inflation in raw and other material costs in 2026, including on purchased components, which is likely to have an adverse effect on our margins to the extent we are unable to pass on such higher costs to our customers.”

Mueller operates manufacturing facilities in Israel (among its ten plants in the U.S., Israel and China); the Israel–Hamas war temporarily shut down its Ariel, Israel facility in October 2023 and caused supply-chain challenges hindering efficient production of its Israel-made products — a recurring geopolitical disruption risk to that part of its manufacturing base.

“In October 2023, the Israel-Hamas war caused a temporary shutdown in our facility in Ariel, Israel. While we reopened the facility in November 2023, the war caused supply chain challenges that hindered our ability to most efficiently manufacture our products produced in Israel.”

Tariffs directly hit Mueller's metal-intensive products: U.S. tariffs apply to imports from all of its supplier countries and to specific commodities used in its operations — steel, aluminum and copper — raising raw-material costs, while U.S.–China trade tensions have placed tariffs on certain of its product categories; further tariffs or retaliation could force price increases or margin compression.

“the Trump administration has implemented tariffs on foreign imports into the United States from all of our supplier countries, as well as on specific commodities used in our operations, such as steel, aluminum, and copper. The materials subject to these tariffs can be expected to impact our raw material costs as well.”