Unico Calibration Filters Each S-90-9101 by Unico GROUP: Lab Equipment & Accessories:Chemistry:Miscellaneous Item Description: Calibration Filter Set Includes: 10%T Filter, 50%T Filter, Didymium Filter, Factory Certified (DROP SHIP ONLY) Packaging Desc: Set Filter Calibration (Drop) Country of Origin: Harmonized Tariff Code: Product Description: