Test gas in reusable cylinder "Ecomini" with 1000 ppm methane (CH4) in synthetic air. 0.85 litre cylinder size at 37 bar Volume: approx. 31.5 litres Please return the empty cylinders to Esders GmbH after use. We will refill them. As a thank you for your contribution to environmental protection, you will receive a free package of 100 Esders Connect measurements.