Lapping film, in telecommunications, is a precision coated abrasive consumable mainly used for processing and polishing optical fiber connectors. [1] It is made from a polyester base sheet, coated with precisely graded minerals [2] such as diamond, [3] aluminium oxide, [4] silicon carbide, silicon oxide or cerium oxide. [5] Lapping film is designed to provide a uniform, consistent finish on optical fiber connector end tips to ensure efficient light/signal transmission. [3] It is available in 0.01-45 μm grades, with or without pressure-sensitive adhesive (PSA) backing.[ citation needed ]