The original Dynavap Cap has been updated with a new functional geometry, which adds even more utility to this rather useful component of their battery free VapCaps. The new design helps keep the Cap in place while also allowing for a more even distribution of the airflow as well as an improved tactile indication of both the heat up and cool down clicks.  In addition, it provides for a free movement or spin of the cap, just in case you like things that spin.