Swan neck adapters are laboratory glassware accessories used to connect two pieces of glassware with different joint sizes. They consist of two parts: a larger socket that fits onto a larger joint, and a swan neck-shaped cone that fits into a smaller joint. The swan neck design of the adapter allows for a more flexible and versatile connection between the glassware components, especially in cases where there is limited space or the components are at different heights.

The swan neck adapter is commonly used in chemical experiments, especially in the areas of distillation and reflux, where it is important to have a secure and leak-proof connection. The adapter ensures a tight seal between the glassware components, minimizing the risk of leakage or contamination during the experiment.

The swan neck design of the adapter also allows for a more ergonomic setup, making it easier to access and manipulate the components.