Expansion adapters are laboratory glassware accessories used to connect two pieces of glassware with different joint sizes. They consist of two parts: a smaller socket that fits onto a smaller joint, and a larger cone that fits into a larger joint. The expansion adapter allows two glassware components with different joint sizes to be connected, allowing for versatility and flexibility in laboratory setups.

The 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 expansion adapter ensures a tight seal between the glassware components, minimizing the risk of leakage or contamination during the experiment.

The use of expansion adapters allows for the integration of different glassware components into a single setup, making it a useful tool for laboratory professionals.