Coating bonded to a flexible fused silica core, yielding a more suitable coating on a less breakable fiber. There may be a slight difference in extraction selectivity compared to the same coating on a standard fused silica core.. Material: StableFlex fiber. 24 ga Needle size. Pack of 3. . . Sigma-Aldrich 57329-U SPME Fiber Assembly Divinylbenzene/Carboxen/Polydimethylsiloxane for Autosampler, DVB/CAR/PDMS, 24 ga Needle Size, Pack of 3. Country of Origin : United States. Part Number : 1195D85EA. Pack of : 3.