The Shimano Calcutta Conquest MD Spare Spool gives anglers a replacement or backup spool for the Shimano Conquest MD Round Casting Reel (FishUSA SKU# F27558), making it easy to keep alternate line setups ready for muskie, pike, salmon, and other hard-pulling fish. Shimano S3D technology uses a balanced, uniform thin-wall aluminum spool to significantly reduce vibration during rotation. The result is a smoother feel through the cast and retrieve, helping anglers maintain consistent spool performance when throwing large plugs, swimbaits, bucktails, and other demanding presentations. Spare spools for the Shimano Conquest MD Round Casting Reel (FishUSA SKU#: F27558) S3D technology reduces spool vibration Balanced thin-wall aluminum construction Smooth casting and retrieving performance Manufacturer's one-year limited warranty