Formaldehyde 0.05-4.0 ppm Gas Detector Tube, pk/10 Back Catalog number: 171SC Manufacturer: SENSIDYNE Availability: In the manufacturer's stock Price on request - + Recommended 800074 Tube Holder Triple Variable Flow, only Price on request 800149 Single Tube Holder Kit, 6 x 70mm (Standard Charcoal Tube) Price on request 800064-10 Tube Holder Housing End, 5/8", for 7-10mm (Packg of 10) Price on request