Tube Holder Housing, 5 x 150mm, 1/2", S255 Back Catalog number: 200104 Manufacturer: SENSIDYNE Availability: In the manufacturer's stock Price on request - + Recommended 106SC Carbon Monoxide 1-50 ppm Gas Detector Tube, pk/10 Price on request 171SC Formaldehyde 0.05-4.0 ppm Gas Detector Tube, pk/10 Price on request 800073 Tube Holder Dual Variable Flow, only Price on request