Zeus A225S Vortec Alternator with RegulatorThe highest power output alternator in its size/class. Features: Engineered for High Energy Production. Suitable for Marine, RV, Military, and Commercial applications. Rapidly charges large battery banks. Coolest operating temperatures for increased performance. Runs 8 - 20% cooler than incumbent alternators due to: Heat shedding coatings Rectifier located on housing exterior Dual cooling fans OEM Components Optimized for performance at idle speeds. Reduces the need for a generator by creating additional power with your engine. Unleash peak performance with E-Coat/Cerakote. Our advanced coating absorbs less heat, keeping the A225S cooler. This translates to more amperage for sustained periods. For maximum performance or lithium battery charging, use an ARCO Zeus Bluetooth alternator regulator. SAE J1171 Certified. Proudly made in the U.S.A. Technical Specifications: Voltage - 12v Field Type - P Rotor Poles - 16 Stator Size - 130mm Frame Size - Small Weight - 12lbs/6.7kg Regulation - Internal/External Output Voltage - 14.1v (default) Finish - (Black) Cerakote or E-coating Cut-In RPM - 1,061 Alternator RPM Maximum Alt RPM - 19,000 Battery Post - M8 Thread Post, Side Mount Standard Pulley - 49K6 (6-groove, 49mm) Pulley Mount - 17mm diameter shaft, 25mm long, threaded M17 x 1.5 Pulley Hardware - M17 x 1.5 x 24mm nut, w/ 18mm ID x 29mm OD washer (Included) Diodes - 6 positive, 6 negative, 50A Rated, Avalanche Max Output (Cold, 9,000 RPM) - 254 Amps Sustained Cruising Output (Hot, 6,000 RPM) - 187 Amps Sustained Idle Output (Hot, 3,000 RPM) - 157 Amps Mounting Application:Replaces Mando type alternators using Vortec/ GM pad mounting feet (Found on many Mercruiser and Volvo Penta 3.0GLM, 3.0GLP, 4.3GXi, 5.7GiL, 5.7GXiL Marine Engines.) (GM Blocks)