hook shaped prongs 64a 64b and 70a 70b projecting from the clamp block 40 respectively can readily be deformed elastically at the part near the root since said clamp block is molded from plastic material thus each of the prongs 64a 64b 70a and 70b can easily be fit in the recess 42 of the reel hub body 41 by way of the outer surfaces 90a 90b 91a and 91b of the hook shaped parts 66a 66b 72a and 72b respectively since said outer surfaces serve as guide surfaces after fitting the hook shaped parts 66a 66b 72a and 72b at the ends of the prongs 64a 64b 70a and 70b return to their original states so that they are locked adequately within the female cavities 80a 80b 81a and 81b respectively formed in the inner surfaces 46a and 46b of the recess 42 and held securely in this embodiment the clamp block 40 requires relatively small pressure in order to be fit so that the effect of the deformation will not extend to the center of the outer surface 60 of said clamp block and is limited to the areas near the roots of the hook shaped prongs 64a 64b 70a and 70b in this way the leader tape 44 is set and secured in the recess 42 of the reel hub body 41 and the tape is secured more tightly at the four local clamping parts formed by the arched inner surfaces of the hook shaped parts 66a 66b 72a and 72b as indicated by the dotted lines in fig2 whenever necessary however the leader tape 44 can be clamped.