The Bureau of ATF plans to award a sole source contract to Environment Growth Chambers (EGC) of Chagrin Falls, OH, to replace major mechanical components and controllers for the Fire Research Laboratory’s large conditioning chamber. EGC is the only provider capable of retrofitting the new controllers to the existing design, as documented in a vendor sole source letter. This notice is issued under the authority that only one responsible source can meet the agency’s requirements. No budget amount is specified, and no performance location beyond the Fire Research Laboratory is mentioned. This is not a request for quotations, and no submission timelines are provided.