We the leading professonial glass test tubes (including screw cap manufacturer and exporter in china, supply good ss or borosilicate glass. Size: 10x75mm, 10x100mm, 12x75mm, 12x100mm, 13x100mm, 15x100mm, 15x150mm, 16x100mm, 16x125 mm, 16x150mm, 18x150mm, 18x180mm, 20x150mm, 20x200mm etc. Specification: round bottom or flat bottom, print words or not print words Figure:transparent, screw, heat