A strain relief for protection of electrical and other cords extending from a component. The first cutter is movably supported by the first cutting guide and is capable of cutting the rolled media substantially parallel to the unrolling path. The crystallization method is applied to a polycrystalline silicon thin-film transistor manufacturing method including the steps of forming an amorphous silicon thin-film on a glass substrate, and crystallizing the amorphous silicon of the thin-film transistor according to a scanning method using a linear light beam. The components are all contained in the carrier which is preferably a small container that can be attached to a user’s trousers or around the limb of a wearer. More particularly, the invention relates to effective, simplified and highly accurate techniques for calibration of magnetic sensors and accelerometers.