Tube Holder Kit, Dual Variable Manifold (Includes Back Catalog number: 800251 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 800074 Tube Holder Triple Variable Flow, only Price on request 811-9902-20 Charcoal Tube, Coconut Shell, Large, 200/400mg, 8x Price on request