Boating Essentials - 3" Nickel-Plated Heavy-Duty Battery Clips - BE-EL-51011-DP These 3" heavy-duty battery clips from T-H Marine are nickel-plated for superior corrosion resistance compared to traditional copper-plated clips. 3" Nickel-Plated Heavy-Duty Battery Clips High-Impact Plastic Clips with Nickel-Plated Steel Contacts Color-Coded Red for Positive Black for Negative Superior corrosion resistance compared to traditional copper-plated clips