The National Institute of Standards and Technology (NIST) is seeking information from suppliers capable of providing twelve dual-wavelength, ultra-high reflectivity mirrors for use in primary acoustic measurement systems. The mirrors must achieve 99.97% reflectivity at both 1560 nm and 390 nm, with optical losses of 0.015% or lower, and meet specific substrate and coating specifications. This is a sources sought notice for market research only, not a solicitation for bids. Performance of services is at NIST’s Quantum Measurement Division, though no specific location is provided. No budget amount or submission deadline is specified in this notice.