http://www.pneumax.co.za/home/products?page=shop.browse&category_id=13 | Isaiah pneumatic valves are of high quality. They’re used to manage the direction of the airflow in machinery. They also control the level of output pressure. Pneumax is South Africa’s leading supplier of pneumatic valves, solenoid valves and rodless cylinders. They supply all three models of the Isaiah check valves.