Tube Holder Dual Variable Flow, only Back Catalog number: 800073 Manufacturer: SENSIDYNE Availability: In the manufacturer's stock Price on request - + Recommended 811-9981-50 Sorbent Tube, Porapak-N, 6X70, 88/44, 50/BX Price on request 200112-10 Tube Holder Housing, 7-10 x 150mm, 5/8", L255 (Pac Price on request 800249 Tube Holder Kit, Quad Variable (Includes 6x70mm, 7 Price on request