The Red Head Brass style #37 rigid female to male rockerlug adapter is made of hardcoat anodized aluminum. This process provides the completed part with a hardened surface that resists corrosion, abrasion, and reduces electrolysis. It also prevents excessive wear on the threads and complies with NFPA 1963, 4.12 Corrosion Resistance. The style 37 adapters are available in sizes 3/4" - 6". For additional sizes or threads please contact us for a quote.