Caspian and Tanfoglio magazine springs are a focused listing for USPSA Open and Limited builds. The page carries the MBX Extreme Duty Z-Max spring for Caspian and Tanfoglio magazines, which suits shooters rebuilding tubes to restore feed reliability. Replace springs across the full rotation on a schedule so every magazine behaves the same. Confirm your magazine pattern and tube length before ordering. Fast same-day shipping on most orders at Shooters Connection.