Mesh made of polyester fiber can withstand up to 200 degrees Celsius (392 degrees Fahrenheit). Polypropylene fiber can with stand up to 250 degrees Celsius (482 degrees Fahrenheit). Nylon fiber will melt at about 320 degrees Celsius (632 degrees Fahrenheit). Silver or gold filled wire is used in many high-quality fabrics because it provides some protection from heat and moisture. The most common materials used for body armor are polyethylene terephthalate (PET) and polyurethane (PU). These materials are light and flexible, which means they don't create a lot of drag when running. Armor made from these materials can stop knives, bullets, and other small objects. There are different grades of body armor. The grade of a piece of clothing does not affect how well it protects against violence, but rather what price it sells for. For example, there is functional body armor that you wear under your regular clothes and stylish body armor that you wear with a suit on Monday through Friday and something more casual on Saturday and Sunday. Body armor is available for almost all parts of the body.