A catalyst composition for the polymerization of one or more 1-olefins comprises a transition metal catalyst precursor and a cocatalyst, the transition metal catalyst precursor comprising a contact product of an unsubstituted metallocene compound and an aluminum alkyl compound in a hydrocarbon solvent solution. The stent has an anchor portion which protrudes to a central axis side relative to an inner surface surrounding the cavity portion in the contracted state, and which is displaced to the inner surface side in the expanded state relative to a protruded position in the contracted state. The duration for manufacturing the baguette tray can be shortened, and the loss of material for manufacturing the baguette tray can be reduced. The second elongate member is selectively collapsible and expandable to change a size of the second lumen. The antenna track has an antenna usage volume that is adjustable within a predetermined volume range according to the VSWR value and the antenna efficiency maintained within a first and a second predetermined ranges, and the antenna track has at least one feeding portion and at least one grounding portion.