Mechman's Pulley Finder is your fast-track way to choose the perfect pulley for your Mechman high-output alternator. All Mechman alternators use a standard 17 mm rotor shaft, and pulleys here are categorized by belt rib count — not pulley rib count — so use this tool or the technical drawings to confirm alignment. Mechman guarantees fitment only on its own alternators; using incorrect pulleys on other brands can cause misaligned belts, poor thread engagement, or pulley failure.