Erlenmeyer Flasks are conical in shape. The small mouths are designed to be easily stoppered or connected to other labware. The shape also allows the contents of the flask to be mixed with minimal chance of escape due to the smaller size of the flask's mouth. The neck allows the flask to be held with one hand while the other is free to handle other materials. Most flasks have graduated markings to show how much they are filled with reasonable accuracy.
