Made in Massachusetts, Fadespace Quartz are made from ultra purity semiconductive grade momentive quartz. Fadespace consists of master scientific glassblowers with over 83 years of experience. Momentive Quartz is manufactured from silica sands mined in Spruce Pine, North Carolina, these silica sands are the most chemically pure in the world. Ultra pure material and meticulous quality control creates a quartz product built to last. XL Size single cups and Thermals will work with most xl carb caps, while the jumbos require a larger cap like a Chad Bro directional flow cap.