This is the cap for the new wave of dish loading nails. One more of those best of man and machine projects
Marbles are great and all, but...
Ultra pure quartz with machine precision lensing and optical polish for perfect seals.
Insulative. Quartz is significantly more insulative than borosilicate, and the handle allows for safe operation.
Improved airflow - the cone both augments rotational energy and deflects vapor from going directly to the stem.
Widely compatible - these caps fit 16-30mm tops. Deeper cones may interfere with valves.