HydroAir 4″ Retrofit Bulkhead Fitting – 1-1/2″ MPT Product Overview As a retailer of hot tub spare parts, I offer this specialized HydroAir retrofit bulkhead fitting, designed for upgrading existing installations with a 4″ face and 1-1/2″ male pipe thread connection. Key Features 4″ retrofit design 1-1/2″ male pipe thread Professional-grade materials Retrofit-specific engineering Leak-proof construction Universal compatibility Technical Specifications Specification Detail Manufacturer HydroAir Model Number RE415T101 Face Diameter 4 inches Thread Size 1-1/2″ MPT Design Type Retrofit Material High-impact thermoplastic Application Through-wall mounting Sealing Multi-point system Applications Perfect for: System upgrades Existing installation modifications Through-wall installations Spa renovations Equipment updates Replacement projects Installation Features Engineered for retrofit situations with: Easy alignment design Adaptable mounting options Secure sealing system Flexible installation capability Simple retrofit process Design Benefits Compatible with existing openings Simplified upgrade process Reliable sealing Durable construction Professional finish