Introducing our factory-made {18mm screw for GC GCMS instrument clear headspace vial metal caps}. Crafted with precision, durability, and expertise, these caps are designed to perfectly fit your headspace vials for gas chromatography and mass spectrometry instruments. Made from high-quality metal, the caps ensure a secure seal and prevent any leakage during analysis. With their smooth and clear headspace design, these caps facilitate easy monitoring and analysis of volatile compounds. Trust our factory's commitment to delivering superior products that enhance the efficiency and reliability of your laboratory experiments.