9/11/2020 · Nov. 9th, 2020. The Snap Vial is made of USP Type 1, Class A, 33 Borosilicate Glass or USP Type 1, Class B, 51 Borosilicate Glass. The Snap Top PP Cap uses high-quality PP material, which is easy to operate and can be heard when pressed down. With a click, the seal is in place.