Alternator 120 AMP 12V 1-2" Single Foot Spindle Mount J10 Pulley with Isolated GroundAlternator, 621 Series, 120A, 12V, Spindle Mount (Single Foot), 1-2in, J10 AltMount Serpentine Pulley, Isolated Ground 1" Motorola-Style Mounting.Typical for Westerbeke, Lehman, Hino & Pathfinder Engines 2" Delco-Style Mounting; Typical for Volvo Penta (Gas & Diesel), John Deere, Perkins, Mercruiser, Pleasurecraft, Crusader, Indmar, Marine Power & other GM-based Engines.Replaces: 621-120-SR-IGThis product may not be returned to the original point of purchase. Please contact the manufacturer directly with any issues or concerns. - cis2:mm5mnJlm -Brochure (pdf)