Whale Marine 74556 Whale Seaward Magnesium Anode

Magnesium Anode: Provides a strong source of magnesium for aquariums
Durable Construction: Made from corrosion-resistant materials for long-lasting use
Easy Installation: Ships with all necessary mounting hardware for quick and simple installation
Compatible with Most Aquariums: Fits standard 1.5 inch diameter aquariums
Safe for Fish: Does not produce harmful chemicals or gases that can harm fish