The Runt mouthpiece replacement glass. Made from the thickest Simax glass we can get, right here in Asheville North Carolina by our local glass team. The Runt mouthpiece also works with the Junior, though not with the cap on.
Got this to use with my sbjr for when I’m at home. Adds a little extra cooling. Good price and packaging. Unfortunately the mail brought it a day later than it said it would.