Whether it's offered as standard or an upgrade, we always love kilns that have quart tubing!
Quart tubing provides a cleaner kiln interior and magnifies the heat to the glass. They also support and protect the elements from contamination with foreign materials that could shorten the element life.
In addition, quartz tubes protect the glass from any falling debris from exposed elements. If you fire enamels, the metal oxides can cake onto the elements causing them to sag, and drop colored debris... yuk!
Gail has two kilns at her studio with quartz enclosed tubes and never has to worry that anything will drop on her, or her students' glass.