This is a Sources Sought notice for market research to gauge industry capability and interest in a potential future Multiple Award Contract for the supply of custom-designed power transformers, with a total contract capacity of up to $500 million. The anticipated period of performance is up to 10 years (a 5-year base plus a 5-year option), with the contract expected to be advertised in Fiscal Year 2026. The transformers are for hydropower plants, primarily to support the U.S. Army Corps of Engineers, the Bonneville Power Administration, and the Bureau of Reclamation. The work involves the design, manufacturing, and delivery of transformers but explicitly excludes installation. Respondents must demonstrate extensive experience, as manufacturers must have been engaged in producing similar transformers for a minimum of 10 years.