Roll-on bottles made of plastic can come in a variety of shapes and capacities. Some common shapes for plastic roll-on bottles include cylindrical, oval, and rectangular. The capacity of a roll-on bottle refers to the amount of product it can hold, and is typically measured in milliliters (mL). Plastic roll-on bottles can be made in a range of capacities, from very small (5 mL or less) to larger sizes (50 mL or more). The size and shape of the bottle, as well as the type of product it is intended to hold, will often determine the capacity that is most suitable. Plastic roll-on bottles are a popular choice due to their durability, lightweight nature, and cost-effectiveness compared to other materials such as glass. They are often used for products such as perfumes, essential oils, and medications.