Balmar Alternator 170AMP, 12V, 3.15" Dual Foot K6 Pulley w/Isolated GroundingAlternator 170AMP, 12V, 3. 15" Dual Foot K6 Pulley with Isolated Grounding Balmar offers a wide range of alternator power upgrades designed specifically for marine industry applications. Balmar installs high reliability bearings, robust rectifier diodes and improved heat sinking capabilities on all our alternators to ensure improved system reliability combined with increased charging power. Features: 3. 15" Dual Foot Saddle K6 Serpentine Pulley 170A