An Industrial designer creates or improves products and any other "thing" you may require. An industrial designer may design a new type of bicycle, a new BBQ grill, a computer desk or a retail store installation. Industrial designers can create prototypes and concepts for new objects before they are put into production. Some freelancers charge per project, some per hour worked. Make sure you have defined the requirements for your project and both of you have an understanding in writing of what is expected.