Roundup  Extended Control Weed and Grass Killer Plus Weed Preventer II Ready-to-Use Refill for Comfort Wand or Pump 'N Go Sprayer, 1.25-Gallon No Mixing Or Measuring Refill Roundup Pump N Go Extended Control Sprayers Kills Existing Weeds And Grasses Prevents Regrowth For Up To 4 Months Creates An Invisible Barrier