Holds eight vials while supporting the SPME syringe for consistent fiber immersion depth. Two different sampling stands are available - for 4 ml vials and for 15 ml vials. Each vial puck allows the vial to be rotated to index the vial below the SPME syringe during sampling. A replacement 15 mL vial puck (57358-U) is available for the 4 mL unit. When using headspace 28 mm diameter vials, order the aluminum heating block.