Whitetail Institute Sure-Fire Crop Oil Plus is highly recommended as the surfactant or oil additive that must be used with Slay. Sure-Fire Crop Oil Plus is also highly recommended for use with Arrest Max to control perennial and mature grasses. It is a premium concentrated highly refined seed oil that enhances the efficiency of herbicides. It provides rapid surface wetting and leaf penetration and contains an anti-foaming agent to help users correctly mix the spray solution. Sure-Fire Crop Oil Plus comes in a 1 pint container that treats 2 acres.