MARTIN'S Eraser 41% Glyphosate Roundup Pro Generic Weed Killer Glyphosate 41% Eraser 41% Glyphosate may be used in any area of vegetation. Care should be taken to ensure that non-target vegetation is protected from drift. Mix 2oz of Eraser 41% with 1 gallon of water and apply to unwanted vegetation. 1 gallon of solution will treat up to 1,000 square feet of area. Product should only be applied using stainless steel or plastic sprayers.