The invention aims at providing a heat-shrinkable polyester film which is excellent in tearability along perforations and in break resistance after storage when used as labels of beverage bottles. The elongated body is capable of being rolled up on itself by rolling one of the first and second ends of the elongated body in a direction parallel to the longitudinal axis. It thereby becomes possible to adopt a variety of substrate conveyance forms, as required, such as return conveyance for returning the substrate 5 from a downstream machine to an upstream side of the screen printer 2 and bypass conveyance for letting the substrate sent from an upstream side pass through the screen printer, to thus be conveyed to a downstream machine. Optimization of the RAKE receiver reduces power consumption and costs, enhances performance, and provides extensibility for next-generation architectures. Some implementations disclosed herein may create an image that includes the second portion of the media content and may send the image to a server. The retaining mechanism acts on the cam when the cam is in the unlocking condition and moves into the slot when the cam is in the locking condition thereby to inhibit the cam from returning to the unlocking condition.