The main purpose of runway modeling is to showcase designers' collections for potential buyers. Thus, it is the runway model's job to bring the clothes, accessories, etc. to life. How well the model moves and looks in the clothes can determine how well they sell, which is why designers need to be very selective with their model choices. The standard requirement for most fashion runway models is that they be at least 5'10" and very slender. However, runway modeling is not limited to high-end fashion and tall, thin models. There are many runway opportunities for plus-size models, mature models, child models, and so on. Most runway work is booked through modeling agencies.