19 CFR 10.107 - Equipment and supplies; admission.
(a) There shall be admitted without entry and without the payment of duty or any tax imposed upon or by reason of importation of any article described in section 322(b), Tariff Act of 1930, as amended, subject to compliance with the following conditions:
(1) Before importation or as soon thereafter as possible, and in every case before the expiration of 10 days after importation, a report shall be made to the nearest Customs officer by the person in charge of sending the article from the foreign country, or by the person for whose account it was brought into the United States, stating the character, quantity, destination, and use to be made of the article.
(2) If practicable, the article shall be exported under Customs supervision. In any other case a report shall be made by the person in charge of the exportation as soon as possible after exportation to the Customs officer to whom the arrival was reported, stating the character, quantity, and circumstances of the exportation.
(b) In the case of each article admitted under paragraph (a) of this section, the port director shall satisfy himself as to whether the article was exported within a reasonable time, or that it has been properly expended or destroyed. If an article is so far destroyed, in connection with a use contemplated for it by section 322 (b) that it has only a salvage value, it shall not be required to be exported.
(c) Any article admitted under paragraph (a) of this section which is used in the United States otherwise than for a purpose contemplated for it by section 322(b), or which is not exported within 90 days after its arrival in the United States, or within such longer time as may be specially authorized by the port director or Headquarters, U.S. Customs Service, shall be seized and forfeited to the United States.