Cells Are Manufactured From TIG-Welded 5051 Strong Lightweight Aircraft Aluminum Alloy, 12 Bolt, Heavy-Duty, Aircraft Style, Flush Mount Lid Assembly Cells Are Natural Aluminum Color Or Powder Coated, 2 Pickups, 1 Return, And 1 Rollover Vent Cells Are Available With 0 To 90 Ohm Sending Unit.