Pressure release seals (Aluminum-PR) are designed to open when internal pressure exceeds 3.0±0.5bar. aijiren Techbrand™ Screw Neck Vial, 13-425 Thread, Glass, 4mL. Ideal for storage purposes when used with closed top screw seals. aijiren Techbrand™ Headspace-Vial, SPME Crimp Neck, Clear Glass.