4 OZ, Bed Bug Black Powder, Long Lasting, Kills Even The Toughest Pyrethroid Resistant Bed Bugs, Puffer Bottle Comes Complete With Applicator Brush, Using The Attached Applicator Brush, Apply Dust Evenly As A Light Coating Creating A Barrier Through Which Bed Bugs Must Crawl, Electrical Switch Plate Covers Can Be Removed To Allow Access To Voids, But Dust Shouldn't Be Applied Directly In The Electrical Boxes, Treat The Mattress & Box Spring, Paying Particular Attention To Tufts, Folds & Edges.