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 800232 Tube Holder Kit, Deluxe (Single, Dual, Triple & Quad, all sizes) Price on request 800259 Single Tube Holder Kit, 7-10 x 110mm Price on request 800071-10 Tube Holder Housing End, 5/8", for 1/4" OD, Open End (Packg of 10) Price on request