ENGINEERING SPECIFICATION: ZURN ZN1209-NL4 or ZN1209-NR4 Narrow wall vertical offset siphon jet water closet "rigid system" with 4" size no-hub connections and 2" vent complete with Dura-Coated cast iron main fitting, separable face plate rigidly mounted on fitting, universal floor mounted supports, corrosion resistant adjustable ABS coupling with integral test cap, fixture bolts, trim, stud protectors, rear anchor tie down, and bonded "Neo-Seal" gasket.