Interpool 29991 Fiberglass Step Rod - This Fiberglass Step Rod is for use in a ZAM® steel inground pool installation. ZAM® steel is coated with zinc, aluminum and magnesium for maximum corrosion resistance. Due to its strength, durability and eco-friendly features, ZAM® is used across a number of industries. This material exhibits an exceptional alkaline resistance, even in direct contact with concrete and mortar. Salt spray testing has proven ZAM® has protection in salt and other severe environments. This makes it an ideal choice for saltwater pools!