The National Institute of Standards and Technology (NIST) is conducting market research to identify vendors capable of supplying two High-Performance Optical Atomic Clocks for delivery in Boulder. This is a sources sought notice for planning purposes only, not a solicitation for quotes or proposals. The government will use responses to determine if a small business set-aside opportunity exists for this requirement. All responsible sources, including large and small businesses, are encouraged to submit a capability statement demonstrating their ability to meet the specifications. The location for performance of services is Boulder, and no budget amount is specified.