The practical set consists of three unjacketed polymer optical fibers (2m, 3m, 5m long) with 1mm diameter, one 3m long jacketed optical fiber with 2mm outside diameter (diameter of the core is 1mm). The fibers have a step profile of refractive index of various lengths. The set contains 3 types of polishing films (2 pc of each) with various levels of abrasiveness (0,3 micro, 1 micro, and 9 micro). The set can be used as a spare kit for experiments done by Optical Fiber Demonstration Kit or for your experiments regardless of the OFDK.