More durable, not easy to rust, and high anti-corrosion. Billet battery tray has recessed design compatible with the specific Optima Battery that you bought the tray. Compatible with common optima battery grop sizes, Blue top group 34M, D34M, Red top group 34, 34/78 (DOES NOT FIT 34R), Yellow top group D34, D34/78 ( DOES NOT FIT D75 GROUP SIZE 75).
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