The Department of Commerce, specifically the National Institute of Standards and Technology (NIST), is seeking qualified vendors to provide a 1K helium-4 sorption cooler for its Physical Measurement Laboratory's Faint Photonics Group. The cooler must achieve a cooling capacity of at least 250µW at 1K for a duration of 24 hours, feature a closed-cycle system that operates without additional cryogens, and have a diameter of under 100mm, with a total of three units required. This procurement is critical for advancing research in superconducting-nanowire single photon detectors, and delivery is expected within eight weeks of order placement, with a government acceptance period of 21 business days following installation. Interested vendors should submit their quotations, including technical documentation and pricing, to the primary contact, de Ionne Jones, at deionne.jones@nist.gov.