Flexitanks are large, flexible bags made of polyethylene that can hold up to 24 tons of Bitumen. They are a relatively new packing option in Iran and are becoming more popular due to their low cost and ease of handling. Flexitanks are also more environmentally friendly than drums and jumbo bags, as they use less plastic. However, flexitanks can be less secure than other packing options and may not be suitable for long-distance transportation.