U.S. Customs and Border Protection · CROSS Database · 1 HTS code referenced
Primary HTS Code
9001.90.9000
$46.6M monthly imports
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Ruling Age
32 years
Data compiled from CBP CROSS Rulings, Census Bureau Trade Data · As of 2026-04-29 · Updates monthly
The tariff classification of Mica Light Retarders from theUnited Kingdom
NY 887304 June 21, 1993 CLA-2-90:S:N:N3:114 887304 CATEGORY: Classification TARIFF NO.: 9001.90.9000 Mr. G. L. Clarke F. Wiggins (Meakin) 160 Whyteleafe Road Caterham Surrey United Kingdom CR3 5ED RE: The tariff classification of Mica Light Retarders from the United Kingdom Dear Mr. Clarke: In your letter dated May 10, 1993 you requested a tariff classification ruling. Mica light retarders are typically 1 inch in diameter (25mm), but are also supplied at 19mm, 12.5mm, 10mm, and 50mm diameters. Mica light retarders are made in two ways. The mica light retarders may be sandwiched between optical glass cover plates which are ground and polished to an optical standard. In other cases because of the requirements of the end user, the mica light retarders are unsupported by optical glass cover plates. The function of the mica light retarders is to convert the plane of polarized light to circular or elliptical light. They do not filter light. They function in the visible and the near infrared wavelength ranges. The applications for mica light retarders are in laser optics and electro- optical systems such as spectroscopy, photoelastic stress research, and holographics. The applicable subheading for the mica light retarders will be 9001.90.9000, Harmonized Tariff Schedule of the United States (HTS), which provides for lenses, prisms, mirrors and other optical elements, of any material, unmounted, other than such elements of glass not optically worked; other. The rate of duty will be 8.4 percent ad valorem. This ruling is being issued under the provisions of Section 177 of the Customs Regulations (19 C.F.R. 177). A copy of this ruling letter should be attached to the entry documents filed at the time this merchandise is imported. If the documents have been filed without a copy, this ruling should be brought to the attention of the Customs officer handling the transaction. Sincerely, Jean F. Maguire Area Director New York Seaport