Add-It fertilizer injector, 1&frac12; quart capacity, &frac34; FPT inlet/outlet ASAE award-winning Add-It fertilizer injector 1 quart capacity with " FPT inlet/outlet (female pipe thread) Proportioning fertilizer injector - injection rate is constant A minimum flow rate of 2 GPM and 10 PSI is required to function Perfect for drip and conventional sprinkler irrigation systems