A glass iodine flask is a specialized laboratory glassware used in chemical reactions that involve iodine. The flask is typically cylindrical in shape, with a narrow neck and a screw cap for a secure seal. The flask is made of durable, chemically-resistant glass, and is designed to withstand exposure to iodine and its derivatives.

The flask is commonly used for storing, mixing, and dispensing iodine, as well as for conducting iodine-based reactions. The capacity of the flask can vary, but it is typically small, to accommodate the small amounts of iodine that are used in laboratory experiments. The screw cap provides a secure and airtight seal, which helps prevent leaks and evaporation, and also allows for easy dispensing of the contents.