Tube Holder Quad Variable Flow, only Back Catalog number: 800075 Manufacturer: SENSIDYNE Availability: In the manufacturer's stock Price on request - + Recommended 800064 Tube Holder Housing End, 5/8", for 7-10mm Price on request 811-9982-50 Sorbent Tube, Porapak-P, 6X110, 100/50, 50/BX Price on request F-PRO-1218 Universal Tube Holder System - Instruction Manual Price on request