Pneuchange is the unit of choice in thousands of laboratories for ensuring the Continuity of CO supplies to CO incubators, where loss of gas would be inconvenient, costly or dangerous. These compact units can be bench or wall mounted using the keyholes on the back of the unit. The unique pneumatic logic construction of the unit means that it can be placed anywhere between the gas bottles and the equipment being served, no electrical supplies are involved. These units are suitable for use with all non-corrosive gases. The inlet ports are connected with suitable tubing to the gas bottle regulators. Two pressure gauges indicate the inlet pressures and two coloured indicators show which cylinder is active. On exhaustion of the active bottle, the unit switches automatically to the second bottle. The empty cylinder can be replaced at leisure and without fear of loss of gas from the disconnected regulator or inlet port. Standard port fittings are 1/4" OD (12 mm.) hose tails.