DIG Add-It Proportional Fertilizer Injector with Backflow Device, 1-1/2 Quart, 3/4 Inch FHTEconomical, flexible, and easy to use, the Add It 1 Pint (. 47 L) Automatic Proportional Fertilizer Injector is ideal for feeding lawns, shrubs, trees, flowers, raised beds, vines, and potted plants automatically without a pump, spreaders or hoses. It is constructed of heavy walled, UV resistant PVC without any moving parts for maintenance free operation. No pump or outside power source is required. Simply use the Add It Automatic Proportional