New Automatic Jar Bottle Opener One Touch Electric Jar Opener by 3A1Y No twisting, no pulling, no pain . Effortless automatic action . Powerful enough for new, factory sealed jars. Stores easily in a kitchen drawer, freeing up valuable counter space. Easy to use and suitable for all ages make sure the lid of the jar is completely dry. If it is a very slick lid that is very stuck, it may even be worth roughing up slightly with some sand paper. the Robotwist is designed to work primarily on glass jars. Plastic jars will not likely work. 1 1/2 inch diameter lids are the smallest it is designed to work on. if the batteries are not working, try flipping them or try another set of batteries. If it does not work, let the seller know and they will ship anew one out right away free of carve.