Manifolds are equipped with a vacuum port to connect a standard laboratory vacuum pump. The vacuum pulls the sample through the stationary phase, metered by the stopcocks, to control the speed of the extraction process and the sample flow. Waste and wash solvents are discarded and analytes are collected in sample tubes below the manifold completing the extraction. This 12 Position SPE Vacuum Manifold Kit includes: 1 Glass Replacement Chamber (12 Position) - (N9306620) 1 Cover Gasket (12 Position) - (N9306621) 12 Stopcocks (12 Position) - (N9306624) 12 Polypropylene Needles - (N9306622) 12 Stainless Steel Needles - (N9306623) 1 Drying Attachment (12 Position) - (N9306625)