Test gas in a reusable "Ecomini" cylinder containing 2 Vol% hydrogen (H2). Cylinder capacity: approx. 0.85 litres at approx. 37 bar Contents: 31.5 litres Connection: IG 5/8“-18-UNF-valve connection Please return the empty cylinders to Esders GmbH after use. We will recondition and refill them. As a thank you for your contribution to protecting the environment, you will receive a free package of 100 Esders Connect measurements.