Features and Benefits:•Works with airless, hot-air, and nitrogen plastic welders.•Rod diameter fits perfectly into the standard welding tip of Polyvance's Mini-Weld Airless Plastic Welder.Polypropylene is used on some ATV fenders, dirt bike fenders, gas tanks, car batteries. Most bumper covers nowadays are made from either polypropylene or a polypropyelene blend. Because Polypropylene is very stable (meaning few things will react with it), it is almost impossible to get quality repairs using adhesives, and also why it is used to contain chemicals (gasoline, pesticides, etc.) that would react with other plastics. Welding is the best repair method for polypropylene. The blue color of this rod will match many Blue polypropylene applications where you need a more invisible repair. Each rod is 12 inches (30 cm) long by 1/8th inch (3 mm) in diameter and there are approximately 280 rods in the package.