The Mazzei injector is designed for compatible ozone and chemical-injection applications where venturi-based introduction is needed. An injector is useful because it helps draw ozone or other treatment media into the water stream, supporting more dependable treatment performance and efficient mixing.This replacement is especially useful when the original injector is clogged, cracked, damaged, worn, or no longer drawing correctly. Matching the correct #684 size, 3/4 inch male pipe thread connection, black PVDF construction, and compatible design helps preserve intended fit and operation.The 684-PVDF is a practical service part when a compatible Mazzei system needs an injector to restore dependable venturi performance. Mazzei injector #684 size 3/4 inch MIP black PVDF design Useful when the original injector is damaged or worn Supports cleaner and more dependable ozone injection