Borosilicate Glass is used in Sunda's Seido line of evacuated tube solar thermal collectors.  The glass is manufactured primarily of silica and boron oxide to provide maximum durability and thermal shock resistance. This glass is commonly known as pyrex and is used in a variety of applications. These include laboratory equipment, optical telescopes, kitchen cookware, and even as part of the space shuttle thermal protection system. The round evacuated tube design combined with the 2.5 mm thick borosilicate glass create an unusually strong structure that can withstand hail up to 1.38 inches.

Tempered Glass is used for Sunda's Flat Plate collectors. It is produced in such a manner that if broken, it will break into many small and relatively less dangerous pieces. Glass that is not tempered usually breaks into long, sharp, and hazardous pieces. Tempered glass is substantially stronger than normal window glass but is also difficult to cut. Both Sunda flat plate collectors offer 4 mm thick tempered glass. Two tempered glass options are available:

• Normal tempered glass allows 83% of the sun's light to pass through (transmittance) and makes for an economical choice.
• Low-iron tempered glass achieves light transmittance of 92% and allows greater collector performance.