Ideal for your most demanding sampling needs. Recommended for pH-sensitive work and other highly critical applications. 4.0 mL clear screw-top vial, 15x45 mm. 13-425 threads. Type 1 borosilicate glass. These fit WISP (registered) autosamplers. Packaged: 7-1/8 in. x 5-3/8 in. x 1-1/2 in. Cardboard box; Weight: 521.6 g.