factory outlet soalr glass vacuum tubes(pyrex) 3.3 1.size: OD 3MM-315MM 2. ... Light,medium and heavy factory outlet soalr glass vacuum tubes(pyrex) 3.3size: from 3-315mm, and the tubes ... of 37, 47, 58, 70 for the solar water heater.the high borosilicate glass tube enjoys good heat ... resistance at 121°C: ISO720-HGA1& factory outlet soalr glass vacuum tubes(pyrex) 3.3