Genuine Shimano Anti-Reverse Cam Spring (part #10DCM) — this small spring provides the tension needed to keep the anti-reverse cam properly engaged, ensuring your reel handle locks against backward rotation during hooksets and fights. When this spring weakens or breaks, the anti-reverse system becomes unreliable, causing intermittent handle back-play at the worst possible moments. Cross-references with Shimano part number RD7579. OEM replacement ensures perfect fit and factory performance. Available from Offshore Tackle & Repair in Stuart, FL — your trusted source for genuine Shimano reel parts.