Midwest Electricâs Metallic RV Units Are Manufactured Using 16-Gauge, Galvanized Zinc-Coated Steel and Nema 3R Construction, Which Resists Corrosion and Fading and Provides Lasting Service In Outdoor Applications. Units Are Available In Surface Mount and Earth Burial or Padmount Posts, Offering A Wide Range Of Receptacle Configurations to Fit Your Needs.