Tube Holder Quad Variable Flow, only Back Catalog number: 800075 Manufacturer: SENSIDYNE Availability: In the manufacturer's stock Price on request - + Recommended 811-9978-20 Sorbent Tube, XAD-2, 8X110, 450/225, 20/BX Price on request 800138 Tube Holder Adapter for 5/8" Ends Price on request 800251 Tube Holder Kit, Dual Variable Manifold (Includes Price on request