Safelite manufactures their own products. From the Safelite website:
"About Safelite® Glass Corp.
The nation's largest exclusively domestic producer of windshields for the vehicle glass replacement market, Safelite® Glass Corp. has a manufacturing facility in Enfield, N.C. as well as two distribution centers located in Ontario, Calif. and Braselton, Ga. The manufacturing facility serves all of the Safelite® Group retail units and the customers of Safelite Group's wholesale operations, Service AutoGlass®. The Safelite® Glass Corp. manufacturing and distribution facilities are ISO-9001 certified."
Suggest you contact the glass company you intend to deal with if you are concerned about their product offered.
I have had Safelite replace two windshields for me(Kansas City area shop). The work and product was fine. Like most automotive shops, your experience may vary.