Tube Holder Quad Variable Flow, only Back Catalog number: 800075 Manufacturer: SENSIDYNE Availability: In the manufacturer's stock Price on request - + Recommended 811-9969-20 Sorbent Tube, Silica, DNPH, 6X110, 300/150, 20/BX Price on request 800232 Tube Holder Kit, Deluxe (Single, Dual, Triple & Qu Price on request 800139 Tube Holder Adapter for 1/2" Ends Price on request