Tube Holder Single Variable Flow, only Back Catalog number: 800072 Manufacturer: SENSIDYNE Availability: In the manufacturer's stock Price on request - + Recommended 171SC Formaldehyde 0.05-4.0 ppm Gas Detector Tube, pk/10 Price on request 800075 Tube Holder Quad Variable Flow, only Price on request 200131 Impinger Holder, Double, Aluminum, GilAir/HFS Price on request