The National Institute of Standards and Technology (NIST) is conducting market research to identify vendors capable of supplying two Portable Optical Atomic Clocks, with performance of services in Gaithersburg. This is a sources sought notice, not a solicitation, and no budget amount is specified. Responses must indicate the country of manufacture and include capability statements limited to four pages. The government will use the results to determine if a small business set-aside is possible, with a NAICS code of 334516 and a size standard of 1,000 employees. Interested parties should submit their capability statements by the deadline noted in the notice.