If you're looking for quartz glass for a lab project, I highly recommend checking out https://optitechno.com/. I recently bought quartz glass from them for a research setup, and the quality was excellent. They offer a range of options specifically for lab applications, which makes it easy to find exactly what you need. The website is straightforward, and delivery was fast. I was really satisfied with the purchase and felt their quartz glass met all the requirements for precision and clarity.