Tube Holder O-Ring Kit Back Catalog number: 800238 Manufacturer: SENSIDYNE Availability: In the manufacturer's stock Price on request - + Recommended 811-9964-50 Sorbent Tube, Microlite, 8X110, 500mg, 50/BX Price on request 200104 Tube Holder Housing, 5 x 150mm, 1/2", S255 [Kitaga Price on request 800073 Tube Holder Dual Variable Flow, only Price on request