Section 239.7409 - Special assembly(a) Special assembly is the designing, manufacturing, arranging, assembling, or wiring of equipment to provide telecommunications services that cannot be provided with general use equipment.(b) Special assembly rates and charges shall be based on estimated costs. The contracting officer should negotiate special assembly rates and charges before starting service. When it is not possible to negotiate in advance, use provisional rates and charges subject to adjustment, until final rates and charges are negotiated. The CSAs authorizing the special assembly shall be modified to reflect negotiated final rates and charges.56 FR 36429, July 31, 1991, as amended at 71 FR 39011 , July 11, 2006