The National Institute of Standards and Technology (NIST) is seeking to procure maintenance services for Mettler Toledo mass comparators, with the intention of issuing a Sole Source Award to Mettler Toledo if no alternative sources are identified. The primary objective is to ensure preventative maintenance for ten specialized mass comparators, which are critical for maintaining and disseminating an SI-traceable mass scale to the US Measurement System, as they require periodic adjustments to maintain their high performance. Interested vendors must respond with detailed information about their capabilities and relevant equipment by contacting Elizabeth Timberlake or Tracy Retterer via email, with responses encouraged before the closing date of June 17, 2025. This notice serves as a market research tool and does not obligate the government to award a contract.