Webbing bar slides are hardware used in the manufacturing of seat belt straps and other webbing-based products. They consist of a rectangular piece with a central bar that slides along the length of the webbing, providing an adjustable and secure way to tighten and loosen webbing straps for a customized fit. They are made from durable materials and are widely used in the production of seat belts, backpacks, and other products that require an adjustable and secure closure system.