• Natural Rubber is ideal for multiple injections due to high resealability, but not as easy to penetrate as RR/PTFE. • Standard, moderately priced seals for GC and HPLC. • RR/PTFE has a better purity than NR/TEF, is softer and has less fragmentation, but doesn´t offer the same resealability as NR/TEF. • Temperature resistant from -40°C up to 120°C for NR/TEF + Butyl/PTFE resp. up to 110°C for RR/PTFE.