18 mm Pre-Assm Silver Screw Cap w/ Butyl Red/PTFE Gray Septa (100/pk)

Magnetic Precision-Thread Screw Caps present a convenient alternative to crimp caps designs. Caps come with 18 mm liners already installed. The liners are thinner than typical crimp top headspace liner seals, so they may be more easily pierced by SPME sampling systems. The cap has a 8 mm ceter hole also suitable for SPME. Packaged: 6 in. x 6 in. plastic bag; Weight: 189.6 g.