Plastic caps are used for plastic bottles, while metal with plastic backing is used for glass; plastic caps are commonly made from polyethylene or polypropylene, while metal caps are usually either steel or aluminum. Plastic caps may have a pour spout.Pioneers in the industry, we offer plastic bottle cap - 28 mm gangajal shape, plastic bottle caps 28 mm - agro cap, plastic bottle inner plug - 28 mm, plastic bottle cap - 38 mm patanjali shape, plastic bottles cap - 46 mm and plastic bottle inner plug - 37 mm from India.