Ferrules are made from 100% high-purity graphite with an upper temperature limit of 450° C. Ferrules are precision formed with a flash-free ID and may be reused if not overtightened. One-piece design does not require a back ferrule. 1/16" ferrules are used by most GCs, except Perkin-Elmer which uses 1/8" ferrules.

Please note for all ferrules:
0.4mm ID ferrules fit 0.25mm ID capillary columns
0.5mm ID ferrules fit 0.32mm ID capillary columns
0.8mm ID ferrules fit 0.53mm ID capillary columns

"Straight" ferrules are used for 1/16" OD tubing.