Genuine Shimano Clamp Nut (part #10JCF) — the clamp nut threads onto the rod clamp assembly to securely fasten the reel to the rod seat. A corroded, cross-threaded, or missing clamp nut allows the reel to loosen and shift during use, compromising casting accuracy and fish-fighting control. Cross-references with Shimano part number TGT2092. OEM replacement ensures proper thread engagement and corrosion resistance for saltwater use. Available from Offshore Tackle & Repair in Stuart, FL — your trusted source for genuine Shimano reel parts.