VWR® Autosampler Vials, Inserts and Closures. 2mL, 12x32mm, 8mm Standard Opening Screw Thread Vials and Inserts. • 8-425 thread finish. • Vials feature a write-on patch with graduation for convenient Aijiren Vials and Sample Containment Solutions Brochure. With Aijiren vials, you can rest assured that your sample Crimp cap vs. screw cap .